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KGATW0601HSI
Installation Instructions
TWINNING KIT FOR HSI SINGLE--- AND2---STAGE CONDENSING AND
NON---CONDENSING GAS FURNACES
Please read these instructions completely before starting theinstallation.
TABLE OF CONTENTS
TABLE OF CONTENTS 1
SAFETY CONSIDERATIONS 1. . . . . . . . . . . . . . . . . . . . . . . .
INTRODUCTION 2
DESCRIPTION AND USAGE 2
ELECTROSTATIC DISCHARGE (ESD) PRECAUTION 4. . .
SECTION I: MULTIPOISE SINGLE--SPEED AND TWO--SPEED NON--CONDENSING HSI FURNACEMODELS 5
INSTALL FURNACES 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CONNECT ELECTRICAL COMPONENTS— HEATING 10
CONNECT ELECTRICAL COMPONENTS--COOLING 15
VENTING 15. . . . . .
GAS SUPPLY PIPING 15
ELECTRICAL SUPPLY CONNECTIONS 15. . . . . . . . . . . . .
START--UP AND ADJUSTMENT 18
SEQUENCE OF OPERATION 20
SECTION II: SINGLE--SPEED AND TWO--SPEEDMULTIPOISE CONDENSING HSI FURNACEMODELS 21
INSTALL FURNACES 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CONNECT ELECTRICAL COMPONENTS — HEATING 28
CONNECT ELECTRICAL COMPONENTS— COOLING 31
VENTING 32
GAS SUPPLY PIPING 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CONDENSATE DRAIN CONNECTIONS 32
ELECTRICAL SUPPLY CONNECTIONS 32. . . . . . . . . . . . .
START--UP AND ADJUSTMENT 32. . . . . . . . . . . . . . . . . . . .
SEQUENCE OF OPERATION 33
SAFETY CONSIDERATIONSInstalling and servicing heating equipment can be hazardous due togas and electrical components. Only trained and qualifiedpersonnel should install, repair, or service heating equipment.Untrained personnel can perform basic maintenance functions suchas cleaning and replacing air filters. All other operations must beperformed by trained service personnel. When working on heatingequipment, observe precautions in literature, on tags, and on labelsattached to or shipped with unit and other safety precautions thatmay apply.
These instructions cover the minimum requirements and conformto existing national standards and safety codes. In some instances,these instructions exceed certain local codes and ordinances,especially those that may not have kept up with changingresidential construction practices. We require these instructions as aminimum for a safe installation.
Wear safety glasses and work gloves. Have a fire extinguisheravailable during start--up and adjustment procedures and servicecalls.
Recognize safety information. This is the safety--alert symbol .When you see this symbol on the furnace and in instructions ormanuals, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, andCAUTION. These words are used with the safety--alert symbol.DANGER identifies the most serious hazards which will result insevere personal injury or death. WARNING signifies a hazardwhich could result in personal injury or death. CAUTION is usedto identify unsafe practices which may result in minor personalinjury or product and property damage. NOTE is used to highlightsuggestions which will result in enhanced installation, reliability, oroperation.
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injuryor death.
Turn off gas and electrical supplies to unit and install lockouttag before beginning any installation or modification. Followoperating instructions on label attached to furnace.
! WARNING
2
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use careand wear appropriate protective clothing and gloves whenhandling parts.
CAUTION!
INTRODUCTIONIMPORTANT: Only the furnace sizes listed in Tables 2, 3 and 4can be twinned. Both furnaces must have the same productnumber, including heating and cooling sizes, to achieve correctoperation.
This furnace twinning kit P/N KGATW0601HSI permitsconnection to the following furnaces to operate as a single unit onthe same duct work:S 2 multipoise, 33.3 inch (846 mm), single--speed,
non--condensing furnaces (See Fig. 1, 2, and Table 2.)
S 2 multipoise, 33.3 inch (846 mm), 2--stage, non--condensing
furnaces (See Fig. 1, 14, and Table 2.)
S 2 multipoise, 40 inch (1016 mm), single--speed, condensing
furnaces (See Fig. 22, 23, and Table 3 or 4.)
S 2 multipoise, 40 inch (1016 mm), 2--stage, condensing furnaces
(See Fig. 22, 23, and Table 3 or 4.)
UNIT AND PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in unit and propertydamage.
A non--condensing furnace shall NOT be twinned with acondensing furnace. Two--stage condensing ornon--condensing furnaces shall not be twinned with any singlestage furnace. Do not twin furnaces that have a differentnumber of blower motor speed taps together. Furnaces shallonly be twinned in the positions shown. Variable--speedfurnaces shall not be twinned.
! WARNING
DESCRIPTION AND USAGERefer to the appropriate section for your furnaces.
SECTION I: Models 58STA, 58STX, 58DLA, 58DLX, 310AAV,310JAV, 311AAV, 311JAV, PG8MAA, and PG8JAA MultipoiseSingle--Speed Non--Condensing HSI FurnacesS Single--Stage Heat with Single--Stage Gas--Heat Thermostat
S Two--Stage Heat with 2--Stage Gas--Heat Thermostat
S Models 58CTA, 58CTX, 312AAV, and 312JAV, Multipoise
2--Stage Non--Condensing HSI Furnaces
S Two--Stage Heat with Single--Stage Gas--Heat Thermostat
S Two--Stage Heat with 2--Stage Gas--Heat Thermostat
SECTION II: Models 58MCA, 58MCB, 58MSA, 58MXA,58MXB, 340AAV, 340MAV, 345MAV, 350AAV, 350MAV,490AAV, PG9MAA and PG9MAB Multipoise Single--SpeedCondensing HSI FurnacesS Single--Stage Heat with Single--Stage Gas--Heat Thermostat
SECTION III: Models 58MTA, 58MTB, 352MAV and 352AAVMultipoise 2--Stage Condensing HSI Furnaces
S Two--Stage Heat with Single--Stage Gas--Heat Thermostat
S Two--Stage Heat with 2--Stage Gas--Heat Thermostat
DUCT CONNECTIONSAll furnaces must have a common supply plenum attached to thefurnaces or evaporator coils prior to any branch supply trunk ortake--off. The height of the plenum should be at least as high(upflow/downflow) or as long (horizontal) as the width of onefurnace. Supply air dampers, when used should be installed in thebranch ducts, not in the common plenum. Fire or smoke dampers,when required by code may be installed in the common plenum.Refer to the damper manufacturer’s ratings installation instructionsfor proper application. The damper should not create unduerestriction in the open position.
All furnaces must be installed to ensure sufficient return air to bothfurnaces:S For upflow furnaces: A combination of 1 full side of each and
bottom inlet plenum or bottom only inlet plenum shall be used
for return air to each furnace. The preferred method is to have all
return air brought into the bottom of the furnaces through a
common bottom plenum. The bottom return--air plenum shall be
at least as high as the width of the furnace bottom return--air
opening. When there are height limitations, the bottom
return--air plenum height can be reduced to 8 in. minimum if 1
entire side return--air opening of each furnace is used in
conjunction with the bottom return opening. Rear inlet plenums
shall not be used. (See Fig. 1.) Connect all return trunks or
branch return ducts to common return plenum.
S For downflow and horizontal furnaces: All return air must be
brought into the bottom opening of the furnace through a
common return air plenum. The return--air plenum shall be at
least as long (horizontal) or tall (downflow) as the width of the
furnace return--air opening. (See Fig. 2). Connect all return
trunks or branch return ducts to common return plenum.
S For all furnaces: Fire or smoke dampers, when required by
code may be installed in the common return plenum. Refer to
the damper manufacturer’s ratings installation instructions for
proper application. The damper should not create undue
restriction in the open position.
FIRE HAZARD
Failure to follow this warning could result in improperauxiliary limit operation, fire, personal injury or death.
Do not remove the center return--air partitions between thefurnaces.
! WARNING
Staged heating operation is permitted only with this twinning kit.With the single--speed, non--condensing, and condensing furnaces,the left--hand furnace is used for first--stage heat, and both furnacesare used for second--stage heat. With the 2--stage, non--condensingand condensing furnaces, low--gas heat in both furnaces is used forfirst--stage heat, and high--gas heat in both furnaces is used forsecond--stage heat. This kit ensures both furnace blowers operatesimultaneously so air flows through the duct work rather thanrecirculating in a loop between the furnaces.
KGATW
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A02223
Fig. 1 -- Upflow Ductwork Connections
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A02224
Fig. 2 -- Downflow/Horizontal Ductwork Connections
KGATW
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Table 1 – Kit ContentsDESCRIPTION PART NO. QUANTITYSealing tape 2
External extension harness 327962-701 1
Main twinning harness 327957-701 1
Secondary twinning harness 327959-701 1
Two-stage furnace wiring diagram 327891-101 1
Single-stage furnace heat wiring diagram 327893-101 1
Single-stage furnace/two-stage heat wiring diagram 327892-101 1
Label 327956-101 1
Tape 1
Bag Assembly includes:Snap bushing 2
Screws (HEX HD 6B X ¾) 10
Screws (flat head) 1
Wire tie 4
Clamps 2
Installation Instructions 1
NOTE: As a result of staged heating with single--speed furnaces,the air temperature distribution in the supply plenum may beuneven when only 1 furnace is heating.
NOTE: Refer to the Installation, Start--Up, and OperatingInstructions supplied with each furnace for information on venting,clearances, start--up, maintenance, and other information notcovered in this publication.
See Table 1 for kit contents.
ELECTROSTATIC DISCHARGE (ESD)PRECAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit andcomponent damage.
Failure to follow this caution could result in unit andcomponent damage. Electrostatic discharge can affectelectronic components. Take precautions during furnaceinstallation and servicing to protect the furnace electroniccontrol. Precautions will prevent electrostatic discharges frompersonnel and hand tools which are held during the procedure.These precautions will help to avoid exposing the control toelectrostatic discharge by putting the furnace, the control, andthe person at the same electrostatic potential.
CAUTION!
1. Disconnect all power to the furnace. DO NOT TOUCHTHE CONTROL OR ANY WIRE CONNECTED TO THECONTROL PRIOR TO DISCHARGING YOUR BODY’SELECTROSTATIC CHARGE TO GROUND.
2. Firmly touch a clean, unpainted, metal surface of the fur-nace chassis which is close to the control. Tools held in aperson’s hand during grounding will be satisfactorily dis-charged.
3. After touching the chassis you may proceed to service thecontrol or connecting wires as long as you do nothing thatrecharges your body with static electricity (for example; DONOT move or shuffle your feet, DO NOT touch ungroun-ded objects, etc.).
4. If you touch ungrounded objects (recharge your body withstatic electricity), firmly touch furnace again before touch-ing control or wires.
5. Use this procedure for installed and uninstalled (ungroun-ded) furnaces.
6. Before removing a new control from its container, dischargeyour body’s electrostatic charge to ground to protect thecontrol from damage. If the control is to be installed in afurnace, follow items 1 through 5 before bringing the con-trol or yourself into contact with the furnace. Put all usedAND new controls into containers before touching un-grounded objects.
7. An ESD service kit (available from commercial sources)may also be used to prevent ESD damage.
KGATW
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SECTION I: MULTIPOISE SINGLE--SPEED AND TWO--SPEED NON--CONDENSING HSIFURNACE MODELS
SINGLE--STAGE SINGLE--STAGE TWO--STAGE TWO--STAGE
58STA 310AAV 58CTA 312AAV
58STX 310JAV 58CTX 312JAV
58DLA 311AAV
58DLX 311JAV
PG8MAA
AD
E
AD
E
A02235
Fig. 3 -- Dimensional Drawing
Table 2 – Dimensions -- In. (mm) for Two--Stage with PSC Blower
UNIT SIZE A B C VENT CONN.* SHIP WT. – LB.(KG)
045-08/024045 14-3/16 (360) 12-9/16 (319) 12-11/16 (322) 4 104 (47)
045-120/036045 14-3/16 (360) 12-9/16 (319) 12-11/16 (322) 4 107 (49)
070-08/024070 14-3/16 (360) 12-9/16 (319) 12-11/16 (322) 4 111 (50)
070-12/036070 14-3/16 (360) 12-9/16 (319) 12-11/16 (322) 4 115 (52)
070-16/048070 17-1/2 (445) 15-7/8 (403) 16 (406) 4 126 (57)
090-14/042090 17-1/2 (445) 15-7/8 (403) 16 (406) 4 127 (58)
090-16/048090 21 (533) 19-3/8 (492) 19-1/2 (495) 4 140 (64)
090-20/060090 21 (533) 19-3/8 (492) 19-1/2 (495) 4 146 (66)
110-12/036110 17-1/2 (445) 15-7/8 (403) 16 (406) 4 135 (61)
110-16/048110 21 (533) 19-3/8 (492) 19-1/2 (495) 4 146 (66)
110-22/066110 21 (533) 19-3/8 (492) 19-1/2 (495) 4 152 (69)
135-16/048135 21 (533) 19-3/8 (492) 19-1/2 (495) 4 149 (68)
135-22/066135 24-1/2 (622) 22-7/8 (581) 23 (584) 4 163 (74)
155-20/060155 24-1/2 (622) 22-7/8 (581) 23 (584) 4 170 (77)*5---in. or 6---in. (127 or 152 mm) vent connector may be required in some cases.
NOTE: Throughout these instructions, when the furnace installedside--by--side, the left--hand (LH) side will be referred to as the LHfurnace, and the furnace installed on the right--hand (RH) side asthe RH furnace. When the furnaces are installed back--to--back, theleft--hand (LH) side will be referred to as the LH furnace, and thefurnace installed on the right--hand (RH) side as the RH furnacewhen viewed from the side with the extension harness installed.
PROCEDURE 1 — INSTALL FURNACES
A. Upflow/Downflow, Side--by--Side PositionRefer to Fig. 3 and Table 2 for appearance and dimensionaldrawing of twinned furnaces and their connection locations.
1. Select 2 identical heating and airflow furnaces. (See Table2.)
2. Remove outer door and blower access door.
KGATW
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3. For upflow and downflow applications:
a. For upflow applications: Bottom return air usage is re-quired as part of any upflow return air configuration. Ifadditional return air is to enter 1 side of each furnace, inaddition to bottom return air, cut open 1 entire return--air opening in appropriate side of each furnace. (SeeFig. 1.)
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in fire, personalinjury or death.
DO NOT use the back of the furnace for return--air ductconnections, as limit cycling will occur.
! WARNING
b. For downflow applications:Return air can only be connected to bottom opening offurnace. A common return air plenum is required forproper auxiliary limit switch operation. (See Fig. 2.)
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit damage, fire,personal injury or death.
DO NOT use the back or sides of the furnace for return--airduct connections in the downflow position, as limit switchcycling will occur.
! WARNING
4. Remove bottom closure panels from both furnaces. (SeeFig. 4.)
a. Lay furnaces on back or sides.
b. Remove 2 screws from bottom front panel.
c. Pull front panel forward to remove.
d. Remove bottom closure panel and discard.
e. Reinstall bottom front panel.
f. Stand furnaces upright.
5. Apply 2 factory--supplied foam strips to mating side of eachfurnace. Locate strips equal distance from top and bottom asshown in Fig. 5. Trim off excess material.
BottomClosure Panel
Bottom Filler Panel
A10273
Fig. 4 -- Removing Bottom Closure Panel
A10274
Fig. 5 -- Location of Foam Strips
6. Remove 7/8--in. diameter accessory hole knock--outs inblower compartment from mating sides of furnaces. (SeeFig. 3.)
7. Insert a plastic snap bushing through the 7/8--in. knock--outfrom the outside of the casing.
8. Bend or remove the supply flanges as required for upflowor downflow installation. Refer to the furnace installationinstructions for complete details.
9. Position furnaces against each other on return air plenum,supply air plenum or evaporator coil casing. Adjust andshim each furnace to align 7/8--in. diameter holes in bothfurnaces.
10. Drill two 1/8--in. holes, approximately 1 in. (25 mm)belowdischarge flange, from inside top of discharge opening andthrough both furnaces. (See Fig. 6.) Drill two 1/8--in. holes,approximately 1 in. (25 mm)below return air flange, frominside top of return air opening and through both furnaces.(See Fig. 7. as an example).
11. Drive 1 factory--supplied screw through each hole and tight-en until furnaces are secure and foam strips have sealed gapbetween furnaces.
12. Connect return-- and supply--air ducts to furnaces. Seal ductconnections to prevent air leakage.
13. Move 115--v junction box JB in RH furnace (as viewedfrom the upflow position) from left--hand side to right--handside. Refer to furnace installation instructions for completedetails.
14. Go to PROCEDURE 2A for Single Stage Furnaces orPROCEDURE 2B for Two Stage Furnaces.
B. Upflow/Downflow, Back--to--Back PositionRefer to Fig. 3 and Table 2 for appearance and dimensionaldrawing of twinned furnaces and their connection locations.
1. Select 2 identical heating and airflow furnaces. (See Table2.)
2. Remove outer door and blower access door.
3. Remove bottom closure panels from both furnaces. (SeeFig. 4.)
a. Lay furnaces on back or sides.
b. Remove 2 screws from bottom front panel.
c. Pull front panel forward to remove.
d. Remove bottom closure panel and discard.
e. Reinstall bottom front panel.
f. Stand furnaces upright.
4. Applications
KGATW
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A02232
Fig. 6 -- Attaching Furnaces Together at Discharge Opening
a. For upflow applications:Bottom return air usage is required as part of any up-flow return air configuration. If additional return air is toenter 1 side of each furnace, in addition to bottom returnair, cut open 1 entire return--air opening in appropriateside of each furnace. (See Fig. 2.)
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit damage, fire,personal injury or death.
DO NOT use the side of the furnace for return--air ductconnections in the downflow position, as limit cycling willoccur.
! WARNING
b. For downflow applications:Return air can only be connected to bottom opening offurnace. A common return air plenum is required forproper auxiliary limit switch operation. (See Fig. 3.)
5. Apply 2 factory--supplied foam strips to the back of eachfurnace. Locate strips equal distance from top and bottom asshown in Fig. 5. Trim off excess material.
6. Determine which side of furnace will be used to route ex-ternal extension harness. Remove 7/8--in. diameter access-ory hole knockouts in blower compartment side selected toattach harness to. (See Fig. 3.)
7. Bend or remove the supply flanges as required for upflowor downflow installation. Refer to the furnace installationinstructions for complete details.
8. Position furnaces back--to--back on return--air plenum, sup-ply air plenum or evaporator coil casing. Adjust and shimeach furnace to align both furnaces.
NOTE: External extension harness cannot be used on the sameside of the furnace that the return air ducts connect to. Locateharness on opposite side of furnace when side return air is used.
9. Drill two 1/8--in. holes, approximately 1 in. (25 mm)belowdischarge flange, from inside top of discharge opening andthrough both furnaces. (Similar to Fig. 6.) Drill two 1/8--in.holes, approximately 1 in. (25 mm)below return air flange,from inside top of return air opening and through both fur-naces. (Similar to Fig. 7.)
10. Drive 1 factory--supplied No. 6 X 3/4--in. LG screw througheach hole and tighten until furnaces are secure and foamstrips have sealed gap between furnaces.
11. Connect return-- and supply--air ducts to furnaces. Seal ductconnections to prevent air leakage.
A02219
Fig. 7 -- Attaching Furnaces Together at Return Air Opening
12. Move 115--v junction box JB in either furnace from left--hand side to right--hand side if required. Refer to furnaceinstallation instructions for complete details.
13. Go to Step 2A for Single Stage Furnaces or Step 2B forTwo Stage Furnaces.
C. Horizontal, Back--to--Back PositionWhen twinning furnaces in the horizontal position, considerationmust be made to the type of building construction. Attic floorsshould be constructed to support normal live and dead loads of thefurnaces and the person(s) servicing them.
Trusses, wood and metal are engineered for specific applications,and may not support the weight of two (2) furnaces suspendedfrom the top chords or the bottom chords of the trusses. Longhorizontals spans may flex or sag, resulting in damage to thebuilding. Contact the truss manufacturer for additional design andengineering assistance.
Do not suspend furnaces with straps or suspend furnaces from roofdecking.
For attic installations on a platform (See Fig. 8.):
1. Construct a platform from 3/4--in. (76 mm) (nominal ply-wood), extending out 30 inches (762 mm) from the front ofeach furnace.
2. Maintain all clearances to combustibles per the furnace In-stallation, Start--up and Operating Instructions.
3. Follow all additional building codes.
4. Long truss spans may require additional support along thebottom chord of the truss. Consult the truss manufacturer’sguidelines for engineering assistance.
5. Long rafter or attic joist spans may require additional sup-port along the bottom of the rafter or joist. Consult local orregional building codes for design and loading require-ments.
For suspended installations (See Fig. 9.) Not recommended forwood trusses unless approved by the truss manufacturer or otherapproved engineering methods):
1. Furnaces may be suspended using two (2) pieces of1--1/2--in. x 1--1/4--in x 1/4--in. thick cold rolled angle ironunderneath the furnaces and four (4) 3/8--in. diameterthreaded rods.
2. Allow for at least 9 inches (229 mm) in front of each doorfor door removal.
3. Each piece of angle iron must be secured to the bottom ofeach furnace with at least two (2) #8 x 3/4--in. sheet metalscrews.
4. Maintain all clearances to combustibles per the furnace In-stallation, Start--up and Operating Instructions.
KGATW
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A10275
Fig. 8 -- Attic Installation of Horizontal Back--to--Back Furnaces
A10276
Fig. 9 -- Suspended Installation for Horizontal Furnaces Back--to--Back
KGATW
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5. Unistrut or similar material may be used, provided that thefurnaces do not sag in the middle or bend or twist at thesupport ends. The support material must be secured to thebottom of each furnace in a manner similar to securingangle iron to the furnace.
Refer to Fig. 3 and Table 2 for appearance and dimensionaldrawing of twinned furnaces and their connection locations.
1. Select 2 identical heating and airflow furnaces. (See Table2.)
2. Remove outer door and blower access door.
3. Remove bottom closure panels from both furnaces. (SeeFig. 4.)
a. Lay furnaces on back or sides.
b. Remove 2 screws from bottom front panel.
c. Pull front panel forward to remove.
d. Remove bottom closure panel and set aside for possibleuse as roll--out protection.
e. Reinstall bottom front panel.
f. Stand furnaces upright.
4. For All Horizontal applications:Return air can only be connected to bottom opening of fur-nace. (See Fig. 2.) A common return air plenum is requiredfor proper auxiliary limit switch operation.
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit damage, fire,personal injury or death.
DO NOT use the side or back of the furnace for return--air ductconnections in the horizontal position, as limit cycling willoccur.
! WARNING
5. Apply 2 factory--supplied foam strips to the back of eachfurnace. Locate strips equal distance from top and bottom asshown in Fig. 5. Trim off excess material.
6. Determine which side of furnace will be used to route ex-ternal extension harness. Remove 7/8--in. diameter access-ory hole knockouts in blower compartment side selected toattach harness to. (See Fig. 3.)
7. Position furnaces back--to--back on attic platform or suspen-ded supports. Adjust and shim each furnace to align bothfurnaces. Follow all clearance to combustible material.
8. If furnaces are installed closer than 12 inches above a deckmade from combustible material, provide roll--out protec-tion as shown in the furnace installation instructions. Thebottom closure pan may be used for this purpose.
NOTE: DO NOT lay furnace down flat on the side that externalextension harness is installed. Raise furnace up a minimum of1--1/2 inches (38 mm) above deck so harness does not rub oncasing or deck.
9. Drill two 1/8--in. holes, approximately 1 in. (25 mm)belowdischarge flange, from inside top of discharge opening andthrough both furnaces. (See Fig. 6.) Drill two 1/8--in. holes,approximately 1 in. (25 mm)below return air flange, frominside top of return air opening and through both furnaces.(Use Fig. 6 as an example).
10. Drive 1 factory--supplied No. 6 X 3/4--in. LG screw througheach hole and tighten until furnaces are secure and foamstrips have sealed gap between furnaces.
11. Connect return-- and supply--air ducts to furnaces. Seal ductconnections to prevent air leakage.
12. Move 115--v junction box JB in either furnace from left--hand side to right--hand side if required. Refer to furnaceinstallation instructions for complete details.
13. Go to PROCEDURE 2A for Single Stage Furnaces orPROCEDURE 2B for Two Stage Furnaces.
D. Horizontal, Stacked TogetherWhen twinning furnaces in the horizontal position, considerationmust be made to the type of building construction. Attic floorsshould be constructed to support normal live and dead loads of thefurnaces and the person(s) servicing them.
Trusses, wood and metal are engineered for specific applications,and may not support the weight of two (2) furnaces suspendedfrom the top chords or the bottom chords of the trusses. Longhorizontals spans may flex or sag, resulting in damage to thebuilding. Contact the truss manufacturer for additional design andengineering assistance.
Do not suspend furnaces with straps or suspend furnaces from roofdecking.
For attic installations on a platform, see Fig. 10:
1. Construct a platform from 3/4--in. (nominal plywood), ex-tending out 30 inches (762 mm) from the front of each fur-nace.
2. Maintain all clearances to combustibles per the furnace In-stallation, Start--up and Operating Instructions.
3. Follow all additional building codes.
4. Long truss spans may require additional support along thebottom chord of the truss. Consult the truss manufacturer’sguidelines for engineering assistance.
5. Long rafter or attic joist spans may require additional sup-port along the bottom of the rafter or joist. Consult local orregional building codes for design and loading require-ments.
For suspended installations, see Fig. 11. Not recommended forwood trusses unless approved by the truss manufacturer or otherapproved engineering methods):
1. Furnaces may be suspended using two (2) pieces of1--1/2--in. x 1--1/2--in. x 1/4--in. thick cold rolled angle ironunderneath the furnaces and four (4) 3/8--in. diameterthreaded rods.
2. Allow for at least 9 inches (229 mm) in front of each doorfor door removal.
3. Each piece of angle iron must be secured to the bottom ofeach furnace with at least two (2) #8 x 3/4--in. sheet metalscrews.
4. Maintain all clearances to combustibles per the furnace In-stallation, Start--up and Operating Instructions.
5. Unistrut or similar material may be used, provided that thefurnaces do not sag in the middle or bend or twist at thesupport ends. The support material must be secured to thebottom of each furnace in a manner similar to securingangle iron to the furnace.
Refer to Fig. 3 and Table 2 for appearance and dimensionaldrawing of twinned furnaces and their connection locations.
1. Select 2 identical heating and airflow furnaces. (See Table2.)
2. Remove outer door and blower access door.
3. Remove bottom closure panels from both furnaces. (SeeFig. 4.)
a. Lay furnaces on back or sides.
b. Remove 2 screws from bottom front panel.
c. Rotate front panel downward to remove.
d. Remove bottom closure panel and set aside for possibleuse as roll--out protection.
e. Reinstall bottom front panel.
KGATW
10
f. Stand furnaces upright.
4. For all horizontal applications: Return air can only be con-nected to bottom opening of furnace.
5. Apply 2 factory--supplied foam strips to mating side of eachfurnace. Locate strips equal distance from top and bottom asshown in Fig. 5.
6. Remove 7/8--in. diameter accessory hole knockouts inblower compartment from mating sides of furnaces. (SeeFig. 3.)
7. Insert a plastic snap bushing through the 7/8--in. K.O. fromthe outside of the casing.
8. Position furnaces on top of each other on platform or sus-pended supports. Adjust and shim each furnace to align7/8--in. diameter holes in both furnaces.
9. Drill two 1/8--in. holes, approximately 1 in. (25 mm)belowdischarge flange, from inside top of discharge opening andthrough both furnaces. (See Fig. 6.) Drill two 1/8--in. holes,approximately 1 in. (25 mm)above return air openingflange, from inside blower compartment and through bothfurnaces. (See Fig. 7.)
10. Drive 1 factory--supplied screw through each hole and tight-en until furnaces are secure and foam strips have sealed gapbetween furnaces.
11. Connect return-- and supply--air ducts to furnaces. Seal ductconnections to prevent air leakage.
12. Move 115--v junction box JB in RH furnace (as viewedfrom the upflow position) from left--hand side to right--handside. Refer to furnace installation instructions for completedetails.
13. Go to PROCEDURE 2A for Single Stage Furnaces orPROCEDURE 2B for Two Stage Furnaces.
PROCEDURE 2 — CONNECT ELECTRICALCOMPONENTS—HEATING
A. All Single--Stage Models: 58STA, 58STX, 58DLA, 58DLX,310AAV, 310JAV, 311AAV, 311JAV, PG8MAA, ANDPG8JAA Multipoise Single--Speed Non--Condensing HSIFurnaces
FIRE HAZARD
Failure to follow this warning could result in fire, personalinjury or death.
Make no connections between the R 24--vac connector in 1furnace and the R 24--vac connector in other furnace.
! WARNING
See Electrostatic Discharge Precaution Section.
A10277
Fig. 10 -- Attic Installation of Horizontal Furnace Stacked Together
KGATW
11
3/8″ Flat Washer
3/8″ Hex Nut
3/8″ Flat Washer
11/2″ x 11/2″ x 1/4″ Angle Iron
3/8″ Lock Washer
3/8″ Theaded Rod
3/8″ Lock Washer3/8″ Hex Nut
A10278
Fig. 11 -- Suspended Installation for Horizontal Furnaces Stacked Together
The twinning kit can be used for single--stage or 2--stage heatingoperation. There are 3 harness assemblies included in this kit. If thefurnaces are side--by--side, only 2 harness assemblies are required.If the furnaces are installed back--to--back, all 3 harness assembliesincluded in the kit must be used.
1. Remove outer doors and blower access doors from both fur-naces.
2. If furnaces are installed back--to--back in any orientation, theexternal Extension Harness must be used. The harness con-sists of:
a. 54--1/2 inches (1384 mm) of 1/2--in. flexible steel con-duit
b. (2) 90_ conduit connectors
c. (1) 4 wire polarized wiring harness d. (1) 2 wire polar-ized wiring harness
3. Install the Extension Harness as follows:
a. Remove lock nuts from the end of each conduit con-nector.
b. Route the end of the harness, labeled “twinning kit har-ness,” that mates to the TRK relay harness from theoutside of the furnace through the 7/8--in. knock--out inthe casing to the blower compartment.
c. Route the end of the harness that mates to the 4--wireharness through the outside of the furnace through the7/8--in. knockout in the casing to the blower compart-ment.
d. Install the lock nuts on the 90_ conduit connectors.
e. Install 2 kit--supplied straps approximately 18 inches(457 mm) from each end of harness.
Single--Stage Heat with Single--Stage Gas--Heat Thermostat(Field--Supplied)
NOTE: This application allows both furnaces to operate as 1furnace in gas heat mode as determined by single--stage thermostatoperation. Both furnaces operate in heating mode simultaneously.See furnace Installation, Start--Up, and Operating Instructions forfurther details on this heating mode.
1. Install harness labeled “Main Furnace” with TKR on L/HFurnace:The Main Harness includes the TKR relay and AuxiliaryLimit switch on the harness. The harness is also tagged“Main Furnace” near the ends of the plug connector.
a. Secure relay of TKR harness assembly to LH furnaceblower housing using 2 factory--supplied screws. (SeeFig. 12.)
NOTE: See Fig. 15 for Single Stage furnace Twinning Kit wiringdiagram.
b. Connect TKR white wire labeled W from TKR to LHfurnace control thermostat connection W.
c. Connect TKR black wire labeled C from TKR to LHfurnace control thermostat connection COM 24V.
d. Connect yellow wire labeled TEST to LH furnace con-trol TEST/TWIN terminal.
e. If Extension Harness was used, connect 4--wire harnessto Extension Harness.
NOTE: If Extension Harness will not plug in to L/H and R/Hfurnaces, extension harness is installed backward. Removeextension harness and re--install in correct orientation.
2. Install Auxiliary Limit Switch (ALS--M) on L/H furnace:
KGATW
12
A10279
Fig. 12 -- TKR Relay Secured with Factory--Supplied Screws
a. Drill 1/8--in. hole in blower housing 12 in. (305mm)below blower shelf. (See Fig. 13.)
b. Position ALS--M so reset button faces front of furnace.
c. Secure bracket to blower housing using a factory--sup-plied screw.
d. Disconnect red transformer wire from LH furnace con-trol SEC--1 connection.
e. Connect red transformer wire connector to ALS--M wireconnector PL7 labeled TRAN.
f. Connect orange ALS--M wire connector labeled DOORSWITCH or SEC 1 to LH furnace control SEC--1 ter-minal.
g. If Extension Harness was used, connect 2--wire harnessto Extension Harness
3. Install Secondary 4--wire harness on R/H furnace:
The Secondary Harness includes the Auxiliary Door Switch andAuxiliary Limit Switch. The harness is also tagged “SecondaryFurnace” near the plug ends of the harness.
a. Connect red wire labeled R--Secondary to RH furnacecontrol thermostat connection R.
b. Connect white wire labeled W--Secondary to RH fur-nace control thermostat connection W.
c. Connect black wire labeled C--Secondary to RH furnacecontrol thermostat connection COM 24V.
d. Connect yellow wire labeled TEST SECONDARY fromLH furnace control TEST terminal to RH furnace con-trol TEST terminal.
e. If the furnaces are side--by--side, route loose ends of4--wire harness from Secondary furnace to Main furnacethrough EWIN snap bushings previously installedbetween furnaces. (See Fig. 4.)
f. Connect Secondary 4--wire harness into 4--wire Mainharness.
g. If Extension Harness was installed, connect 4--wire Sec-ondary Harness to the Extension Harness.
4. Install Auxiliary Limit Switch, ALS--S on Secondary fur-nace:
a. Drill 1/8--in. hole in blower housing 12 in. (305 mm)be-low blower shelf. (See Fig. 13.)
b. Position ALS--S with terminals facing front of furnace.
c. Secure bracket to blower housing using factory--sup-plied screw.
5. Install Auxiliary Blower Door Interlock Switch, ILK--1 onSecondary furnace:
a. Measure along the left edge of the furnace casing, 6inches (152 mm) down from blower shelf.
b. Drill a 3/16--in. clearance hole through front edge ofblower door support.
c. Insert blower door switch mounting tab behind frontedge of blower door support.
d. Secure auxiliary door switch ILK--1 using factory--sup-plied screw.
e. Connect 2--Wire Secondary Harness to 2--wire MainHarness that was routed through furnace casings.
KGATW
13
A10280
Fig. 13 -- Auxiliary Door Switch
f. If extension harness was installed, 2--wire SecondaryHarness from Secondary to Main Extension Harness.
NOTE: If Extension Harness will not plug in to L/H and R/Hfurnaces, extension harness is installed backward. Removeextension harness and re--install in correct orientation.
6. Select identical blower motor speed taps at control centerconnectors in both furnaces.
UNIT DAMAGE HAZARD
Failure to follow this caution may result equipment damage.
Failure to select identical blower speed taps in both furnacescan result in overheating of furnace components and possibleloss of furnace operation and damage to the furnaces.
CAUTION!
7. Dress wires to ensure they do not contact sharp or movingparts nor interfere with blower operation, removal of filters,or operation of switches.
8. Make all thermostat connections to LH furnace only. SeeFig. 15.
Two--Stage Heat with 2--Stage Gas--Heat Thermostat (FieldSupplied)
NOTE: ALL thermostat connections are to be made to LH furnacecontrol ONLY. (See Fig. 16.)
NOTE: This application allows only the LH furnace to operate forfirst--stage heat mode or both furnaces to operate for second--stage
heat mode as determined by a 2--stage thermostat. See furnaceInstallation, Start--Up, and Operating Instructions for further detailson this heating mode.
To operate furnaces in 2--stage heating mode when a 2--stagethermostat controls the staging, install twinning kit as described inSingle--Stage Heat with Single--Stage Gas Heat Thermostat, thenmodify TKR wiring as follows:
a. Disconnect TKR white wire labeled W from the LHfurnace control thermostat connection W.
b. Cut off terminal of TKR white wire labeled W and strip1/4 in. (6 mm).
c. Connect 2--stage thermostat W2 connection to TKRwhite wire labeled W.
PERSONAL INJURY HAZARD
Failure to follow this caution could result in intermittentfurnace operation and unit damage.
Supply--air temperature will be uneven left--to--right whenonly main system is operating.
CAUTION!
NOTE: ALL other 2--stage thermostat connections are to be madeto LH furnace control ONLY. (See Fig. 16.)
B. All Two--Stage Models: 58CTA, 58CTX, 312AAV, 312JAVMultipoise Two--Speed Non--Condensing HSI Furnaceswith PSC Motors
KGATW
14
FIRE HAZARD
Failure to follow this warning could result in fire, personalinjury or death.
Make no connections between the R 24--vac connector in 1furnace and the R 24--vac connector in other furnace.
! WARNING
See Electrostatic Discharge Precaution Section.
The twinning kit can be used for single--stage or 2--stage heatingoperation. There are 3 harness assemblies included in this kit. If thefurnaces are side--by--side, only 2 harness assemblies are required.If the furnaces are installed back--to--back, all 3 harness assembliesincluded in the kit must be used.
1. Remove outer doors and blower access doors from both fur-naces.
2. If furnaces are installed back--to--back in any orientation, theexternal Extension Harness must be used. The harness con-sists of:
a. 54--1/2--in. of 1/2--in. flexible steel conduit
b. (2) 90_ conduit connectors
c. (2) 4 wire polarized wiring harness
d. (2) 2 wire polarized wiring harness
3. Install the Extension Harness as follows:
a. Remove lock nuts from the end of each conduit con-nector.
b. Route the end of the harness labeled “Twinning Kit Har-ness” that mates to the TKR relay harness from the out-side of the furnace through the 7/8--in. knock--out in thecasing to the blower compartment.
c. Route the end of the harness that mates to the 4--wireharness through the outside of the furnace through the7/8--in. knockout in the casing to the blower compart-ment.
d. Install the lock nuts on the 90_ conduit connectors.
Two--Stage Heat with Single--Stage Gas--Heat Thermostat (FieldSupplied) (See Fig. 17.)
NOTE: This application allows both furnaces to operate as 1furnace in gas heat mode as determined by single--stage thermostatoperation. Both furnaces operate in heating mode simultaneously.See furnace Installation, Start--Up, and Operating Instructions forfurther details on this heating mode.
1. Install harness labeled “Main Furnace” with TKR on L/HFurnace: The Main Harness includes the TKR relay andAuxiliary Limit switch on the harness. The harness is alsotagged “Main Furnace” near the ends of the plug connector.
a. Secure relay of TKR harness assembly to LH furnaceblower housing using 2 factory--supplied screws. Twonew screw holes will have to be drilled using a 1/8--inchdrill bit. See Fig. NO TAG for location of holes to bedrilled.
b. Connect TKR white wire labeled W from TKR to LHfurnace control thermostat connection W/W1.
c. Connect TKR black wire labeled C from TKR to LHfurnace control thermostat connection COM 24V.
d. Connect yellow wire labeled TEST to LH furnace con-trol TEST/TWIN terminal.
e. If Extension Harness was used, connect 4--wire harnessto Extension Harness.
f. Turn LHT set--up switch on L/H control board to“OFF.” (See Fig. 14.)
g. Turn LHT set--up switch on R/H control board to “ON.”
NOTE: If Extension Harness will not plug in to L/H and R/Hfurnaces, extension harness is installed backward. Removeextension harness and re--install in correct orientation.
2. Install Auxiliary Limit Switch (ALS--M) on L/H furnace:
a. Drill 1/8--in. hole in blower housing 12 in. (305mm)below blower shelf. (See Fig. 13.)
b. Position ALS--M so reset button faces front of furnace.
c. Secure bracket to blower housing using a factory--sup-plied screw.
d. Disconnect red transformer wire from LH furnace con-trol SEC--1 connection.
e. Connect red transformer wire connector to ALS--M wireconnector PL7 labeled TRAN.
f. Connect ALS--M orange wire connector labeled SEC 1to LH furnace control SEC--1 terminal.
g. If Extension Harness was used, connect 2--wire harnessto Extension Harness
3. Install Secondary 4--wire harness on R/H furnace:
The Secondary Harness includes the Auxiliary Door Switch andAuxiliary Limit Switch. The harness is also tagged “SecondaryFurnace” near the plug ends of the harness.
a. Connect red wire labeled R--Secondary to RH furnacecontrol thermostat connection R.
b. Connect white wire labeled W--Secondary to RH fur-nace control thermostat connection W/W1.
c. Connect black wire labeled C--Secondary to RH furnacecontrol thermostat connection COM 24V.
d. Connect yellow wire labeled TEST SECONDARY toRH furnace control TEST/TWIN terminal.
e. If the furnaces are side--by--side, route loose ends of4--wire harness from Secondary furnace to Main furnacethrough snap bushings previously installed betweenfurnaces.
f. Connect Secondary 4--wire harness into 4--wire Mainharness.
g. If Extension Harness was installed, connect 4--wire Sec-ondary Harness to the Extension Harness.
4. Install Auxiliary Limit Switch, ALS--S on Secondary fur-nace:
a. Drill 1/8--in. hole in blower housing 12 in. (305 mm)be-low blower shelf. (See Fig. 13.)
b. Position ALS--S with terminals facing front of furnace.
c. Secure bracket to blower housing using factory--sup-plied screw.
5. Install Auxiliary Blower Door Interlock Switch, ILK--1 onSecondary furnace:
a. Measure along the left edge of the furnace casing, 6inches (152 mm) down from blower shelf.
b. Drill a 3/16--in. clearance hole through front of blowerdoor support.
c. Insert blower door switch mounting tab behind frontedge of blower door support.
d. Secure auxiliary door switch ILK--1 using factory--sup-plied shallow head screw.
e. Connect 2--Wire Secondary Harness to 2--wire MainHarness that was routed from Secondary to Main fur-nace casings.
f. If extension harness was installed, 2--wire SecondaryHarness to Extension Harness.
NOTE: If Extension Harness will not plug in to L/H and R/Hfurnaces, extension harness is installed backward. Removeextension harness and re--install in correct orientation.
KGATW
15
#2�1��'#:
1�
�
16
�3=��� ���������� #� �2�� ��$��2��
#2�������� #2��������
���$�����$���� ������ 1�� 16
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A02221
Fig. 14 -- LHT Switch Settings
6. Select identical blower motor speed taps at control motorconnectors in both furnaces.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit damage.
Failure to select identical blower speed taps in both furnacescan result in overheating of furnace components and possibleloss of furnace operation and damage to the furnaces
CAUTION!
7. Dress wires to ensure they do not contact sharp or movingparts nor interfere with blower operation, removal of filters,or operation of switches.
8. Make all thermostat connections to LH furnace only.
Two--Stage Heat with 2--Stage Gas--Heat Thermostat (FieldSupplied)
NOTE: ALL thermostat connections are to be made to LH furnacecontrol ONLY. (See Fig. 17.)
NOTE: This application allows both furnaces to operate in lowheat for first--stage heat mode or both furnaces to operate in highheat for second--stage heat mode as determined by a 2--stagethermostat. See furnace Installation, Start--Up, and OperatingInstructions for further details on this heating mode.
To operate furnaces in 2--stage heating mode when a 2--stagethermostat controls the staging, install twinning kit as described inthe two--stage heat with single--stage gas heat thermostat:
a. Turn LHT set--up switch on L/H control board to “ON.”
b. Turn LHT set--up switch on R/H control board to “ON.”
NOTE: ALL other 2--stage thermostat connections are to be madeto LH furnace control ONLY. (See Fig. 17.)
PROCEDURE 3 — CONNECT ELECTRICALCOMPONENTS--COOLING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in fire, personalinjury or death.
Failure to follow warning could result in fire, personal injuryor death. Make no connections between the R 24--vacconnector in 1 furnace and the R 24--vac connector in otherfurnace.
! WARNING
When installing twinned outdoor units with twinned gas furnaces,it is necessary to use a field--supplied 24--vac pilot--duty relay and a
field--supplied 24/115--vac transformer as shown in Fig. 15, 16, or17 to prevent overloading furnace 24/115--vac transformer.
PROCEDURE 4 — VENTING
Refer to Installation, Start--Up, and Operating Instructions suppliedwith each furnace for venting information.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit damage
When common--venting twinned, Category I(negative--pressure venting), non--condensing furnaces,excessive condensate may occur as a result of oversized ventsystems. Dedicated vents and/or proper vent sizing, per thecurrent edition of the National Fuel Gas Code, will reduce thepotential for condensation.
CAUTION!
PROCEDURE 5 — GAS SUPPLY PIPING
NOTE: All gas connections must be made through exposed outerside of each furnace. Do not common connect any connectionother than supply and return--air ducts.
Furnaces are recommended to be provided with a single shutoffvalve. However, individual shutoff valves may be required by localcodes or jurisdictions. Refer to Installation, Start--Up, andOperating Instructions provided with each furnace for additionalgas supply information.
PROCEDURE 6 — ELECTRICAL SUPPLYCONNECTIONS
NOTE: All electrical power connections must be made throughexposed outer side of each furnace. Do not common connect anyconnection other than supply-- and return--air ducts.
1. Each furnace shall be connected to its own 115--vac powersupply. The twinning kit installation interconnects the fur-naces, allowing them to operate as a single furnace. The L1(black) connection to each furnace must be connected to cir-cuit breakers connected to the same service panel 115--vacphase leg.On single--phase (residential) systems, each furnace circuitbreaker should be located directly across from each other inservice panel, or each furnace circuit breaker should be loc-ated on the same side of service panel, but must skip 1 spaceto be connected to the same leg of the 1--phase power sup-ply.On 3--phase (commercial) systems, each furnace circuitbreaker should be located directly across from each other inservice panel, or each furnace circuit breaker should be loc-ated on the same side of service panel, but must skip 2spaces to be connected to the same leg of the 3--phase
KGATW
16
power supply.The proper 115--vac phasing of furnace connections permits24--vac transformer phasing as described below.
2. Phasing of the connected 24--vac transformer secondary cir-cuits can be determined with the LED status of both fur-naces. See furnace Installation, Start--Up, and Operating In-structions and status code labels on blower doors. Thefurnaces’ transformers’ black leads should be connected to
PR1 connectors and white leads to L2 connectors on con-trols. If 1 or both LEDs are rapidly flashing, disconnect leadat TEST/TWIN terminal of LH furnace and observe LED ateach furnace.To verify that the furnaces are in phase, check from Mainfurnace L1 to Secondary furnace L1 with a voltmeter. If thefurnaces are in phase, the voltage between both furnaceswill be ZERO.
IF:a. Both LEDs are on continuously: System phasing is
okay.
b. One or both LEDs are rapidly flashing:
(1.) Line voltage polarity is reversed
(2.) Reverse SEC--1 and SEC--2 in furnace with rapidflashing LED.
c. One LED is off, 1 LED is on continuously:
(1.) The 24--vac circuit is inoperative on furnace withLED light off.
(2.) Check transformers, auxiliary limits, and doorswitches in both furnaces and correct problem.
d. One or both LEDs are dim or flickering. Furnaces areon different phase legs. Disconnect TWIN/TEST lead. Ifboth LEDs are on continuously when TWIN/TEST isdisconnected, furnace line voltage power supply is outof phase.
3. Reconnect lead at TWIN/TEST terminal of LH furnace andobserve LED at each furnace. The LEDs will glow steadyfor proper phasing.
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17
THERMOSTAT MAIN ( LH ) FURNACE
RELAY 1
PLCALS-M
PLA
NOTE #5
Y/Y2
G
W
R
COM
Y1
BLK
WHT
TEST/TWIN
TKR
BLU
SEC-2 SEC-1
TRANWHT
BLK
L2
NOTE #2
PR1
BLK
WHT
RED
YEL
PLB
SECONDARY ( RH ) FURNACE
Y/Y2
G
W
R
COM
Y1
TEST/TWIN
BLU
SEC-2 SEC-1
BLK
WHT
RED
YEL
PLB RED
TRANWHT
BLK
L2
NOTE #2
PR1
MAKE NO THERMOSTAT CONNECTIONS TO
SECONDARY OR RH FURNACE
1
2
ORN
BLURED
EXTENSION HARNESS(IF USED)
PLA
1
2
ORN
BLUILK-1 ALS-S
NOTE #1
ORN
NOTE #3
24 VAC
TRANSFORMER (FIELD SUPPLIED) NOTE #4
115 VACC Y
OUTDOOR UNITNO. 1
C Y
OUTDOOR UNITNO. 2
LEGEND: NOTES:
Y
G
W
R
COM
NOTE #3
NOTE #6
327893-101 REV. A
1. ALS-S and ILK-1 are located in the SECONDARY or RH furnace blower compartment.
2. Primary connections of transformer not shown; refer to furnace wire label.
3. When extension harness is not required PLA and PLB must be routed through holes in casings.
4. Transformer = 115 VAC primary / 24 VAC secondary / 40VA.5. Relays = 24 VAC coils / pilot duty / normally open.6. Y1 and DHUM terminal not available on "RED" LED control board.
NOTE #6
ALS-M MAIN AUX. LIMIT SW., OVERTEMP-MANUAL RESET, SPST - (N.C.)
ALS-S SECONDARY AUX. LIMIT SW., OVERTEMP-MANUAL RESET, SPST - (N.C.)
ILK-1 SECONDARY AUX. BLOWER DOOR INTERLOCK SWITCH, SPST - (N.O.)
PLA 2-CIRCUIT TWINNING KIT CONNECTORPLB 4 - CIRCUIT TWINNING KIT CONNECTORPLC 1 - CIRCUIT TWINNING KIT IN-LINE SPLICETEST/TWIN COMPONENT TEST & TWINNING TERMINALTKR TWINNING KIT RELAY, SPST - (N.O.)TRAN TRANSFORMER - 115VAC / 24VAC
(PART OF FURNACE)115 VOLT WIRINGTWINNING KIT EXTENSION HARNESS (REQUIRED)FIELD WIRINGFACTORY WIRING (TWINNING KIT)
FIELD INSTALLED AIR CONDITIONING WIRING (WHEN REQUIRED)SINGLE STAGE FURNACE & A/C-SINGLE STAGE THERMOSTAT
DHUM DHUM
4
1
3
2
4
1
3
2
FIELDSUPPLIED
RELAY
A02227
Fig. 15 -- Single--Stage Furnace and A/C Single--Stage ThermostatKGATW
18
THERMOSTAT
RELAY 1
PLCALS-M
PLARELAY 2
NOTE #5
Y1
Y/Y2
G
W
R
COMBLK
WHTTEST/TWIN
TKR
BLU
SEC-2 SEC-1
TRANWHT
BLK
L2
NOTE #2
PR1
BLK
WHT
RED
YEL
PLB
Y/Y2
G
W
R
COM
Y1
TEST/TWIN
BLU
SEC-2 SEC-1
BLK
WHT
RED
YEL
PLB RED
TRANWHT
BLK
L2
NOTE #2
PR1
MAKE NO THERMOSTAT CONNECTIONS TO
SECONDARY OR RH FURNACE
1
2
ORN
BLURED
EXTENSION HARNESS(IF USED)
PLA
1
2
ORN
BLUILK-1 ALS-S
NOTE #1
ORN
NOTE #3
24 VAC
TRANSFORMER (FIELD SUPPLIED) NOTE #4
115 VAC C Y
OUTDOOR UNITNO. 1
C Y
OUTDOOR UNITNO. 2
LEGEND:
1. ALS-S and ILK-1 are located in the SECONDARY or RH furnace blower compartment.
2. Primary connections of transformer not shown; refer to furnace wire label.
3. When extension harness is not required PLA and PLB must be routed through holes in casings.
4. Transformer = 115 VAC primary / 24 VAC secondary / 40VA.5. Relays = 24 VAC coils / pilot duty / normally open.6. Y1 and DHUM terminal not available on "RED" LED control board.
NOTES:
W2
Y1
G
W/W1
R
COM
Y/Y2NOTE #3
327892-101 REV. A
NOTE #6NOTE #6
DHUM DHUM
4
1
3
2
4
1
3
2
FIELD INSTALLED AIR CONDITIONING WIRING (WHEN REQUIRED) SINGLE STAGE FURNACE & A/C-TWO STAGE THERMOSTAT
ALS-M MAIN AUX. LIMIT SW., OVERTEMP-MANUAL RESET, SPST - (N.C.)
ALS-S SECONDARY AUX. LIMIT SW., OVERTEMP-MANUAL RESET, SPST - (N.C.)
ILK-1 SECONDARY AUX. BLOWER DOOR INTERLOCK SWITCH, SPST - (N.O.)
PLA 2-CIRCUIT TWINNING KIT CONNECTORPLB 4 - CIRCUIT TWINNING KIT CONNECTORPLC 1 - CIRCUIT TWINNING KIT IN-LINE SPLICETEST/TWIN COMPONENT TEST & TWINNING TERMINALTKR TWINNING KIT RELAY, SPST - (N.O.)TRAN TRANSFORMER - 115VAC / 24VAC
(PART OF FURNACE)115 VOLT WIRINGTWINNING KIT EXTENSION HARNESS (REQUIRED)FIELD WIRINGFACTORY WIRING (TWINNING KIT)
FIELD SUPPLIED RELAYS
MAIN ( LH ) FURNACE SECONDARY ( RH ) FURNACE
A02228
Fig. 16 -- Single--Stage Furnace and A/C Two--Stage Thermostat
PROCEDURE 7 — START--UP ANDADJUSTMENT
Refer to Installation, Start--Up, and Operating Instructions suppliedwith furnaces for detailed information.
1. Shut off all power and gas to both furnaces.
2. Position blower off delay switches on controls in BOTHfurnaces to SAME desired gas heat blower off delay. (SeeFig. 18 and 19.) See furnace Installation, Start--Up, andOperating Instructions for further details.
3. Attach twinning connection wiring label above the existingfurnace wiring label on the inside of the L/H furnace blower
access door. Use the following labels for the following ap-plications:
Single Stage furnaces with single--stage thermostat, 327893–101Single Stage furnaces with two--stage thermostat, 327892–101Two Stage furnaces with single--stage or 2--stage thermostat,327891–101
4. Attach twinning reference label 327956–101 on outside ofblower access door of RH furnace blower door.
5. Turn on power and gas to both furnaces.
6. Reinstall blower access doors on both furnaces.
7. Operate furnaces through 2 cycles in each mode to confirmcorrect operation by operating only thermostat.
KGATW
19
THERMOSTAT
RELAY 1
PLCALS-M
PLARELAY 2
NOTE #5
W2
Y/Y2
G
W/W1
R
COM
Y1
BLK
WHT
TEST/TWIN
TKR
BLU
SEC-2 SEC-1
TRANWHT
BLK
L2
NOTE #2
PR1
BLK
WHT
RED
YEL
PLB
W2
Y/Y2
G
W/W1
R
COM
Y1
TEST/TWIN
BLU
SEC-2 SEC-1
4
1
3
2
BLK
WHT
RED
YEL
PLB RED
TRANWHT
BLK
L2
NOTE #2
PR1
MAKE NO THERMOSTAT CONNECTIONS TO
SECONDARY OR RH FURNACE
1
2
ORN
BLURED
EXTENSION HARNESS(IF USED)
PLA
1
2
ORN
BLUILK-1 ALS-S
NOTE #1
ORN
NOTE #3
24 VAC
TRANSFORMER (FIELD SUPPLIED) NOTE #4
115 VAC C Y
OUTDOOR UNITNO. 1
C Y
OUTDOOR UNITNO. 2
ACRDJ AIR CONDITIONING RELAY DISABLE JUMPERALS-M MAIN AUX. LIMIT SW., OVERTEMP-MANUAL
RESET, SPST - (N.C.)ALS-S SECONDARY AUX. LIMIT SW.,
OVERTEMP-MANUAL RESET, SPST - (N.C.)ILK-1 SECONDARY AUX. BLOWER DOOR
INTERLOCK SWITCH, SPST - (N.O.)PLA 2-CIRCUIT TWINNING KIT CONNECTORPLB 4 - CIRCUIT TWINNING KIT CONNECTORPLC 1 - CIRCUIT TWINNING KIT IN-LINE SPLICETEST/TWIN COMPONENT TEST & TWINNING TERMINALTKR TWINNING KIT RELAY, SPST - (N.O.)TRAN TRANSFORMER - 115VAC / 24VAC
(PART OF FURNACE)115 VOLT WIRINGTWINNING KIT EXTENSION HARNESS (REQUIRED)FIELD WIRINGFACTORY WIRING (TWINNING KIT)
LEGEND:1. ALS-S and ILK-1 are located in the SECONDARY or RH furnace
blower compartment.2. Primary connections of transformer not shown; refer to furnace wire
label.3. When extension harness is not required PLA and PLB must be routed
through holes in casings.4. Transformer = 115 VAC primary / 24 VAC secondary / 40VA.5. Relays = 24 VAC coils / pilot duty / normally open.6. Two-stage heating can be accomplished by one of the two methods:
a. Using one stage thermostat and letting the Main Furnace’�s (LH)algorithm control low and high-heat operation.
b. Using a two-stage thermostat to control low and high-heat operation. (Apply "W2" Wire)
NOTES:
LHTOFFDLY
2O
NO
FF
THERMOSTATTYPE
LEFT HANDLHT SWITCH 1
RIGHT HANDLHT SWITCH 1
13 TWO STAGE
THERMOSTATON ON
W2
Y1
G
DHUM
W/W1
R
COM
Y/Y2
327891-101 REV. A
NOTE #3
NOTE #6
4
1
3
2
DHUM
2 STG FURNACES / 1 STG A/C UNIT - TWO-STAGE OPERATION
FIELD SUPPLIED RELAYS
FIELD INSTALLED AIR CONDITIONING WIRING (WHEN REQUIRED)
OFF ON
DHUM
MAIN ( LH ) FURNACE SECONDARY ( RH ) FURNACE
ONE STAGETHERMOSTAT
A02229
Fig. 17 -- Two--Stage Furnaces and 1--Stage A/C Unit -- One or Two--Stage Thermostat
a. Single--stage gas heating thermostat R--to--W operatesboth furnaces gas heat mode. First stage of a 2--stagethermostat causes LH furnace to operate in gas--heatmode. Second stage of a 2--stage thermostat causes bothfurnaces to operate in gas heat mode.
b. Single stage thermostat operates first or second stage ofa two stage furnace, based on the furnace control boardalgorithm. 2--stage heating thermostat R--to--W/W1 willoperate both furnaces in low heat mode. Thermostat R
to W/W1 and--W2 causes both furnaces to operate inhigh gas--heat mode.
c. Thermostat R--to--G for continuous fan or low--coolingblower.
d. Cooling thermostat R--to--G--and--Y for single--speedcooling blower.
8. Reinstall control doors on both furnaces.
9. Instruct user in operation of furnace and thermostat.
KGATW
20
BLW
NU
ET
RA
LS
TATU
S C
OD
E LE
D
SEC-2 SEC-1
EAC-2 L2
FUSE 3-AMP
0.5 AMP@24VAC
HUM
TEST/TWIN
Y1 D
HU
M G
CO
M W
/W1 Y
/Y2 R
24V
PLT
120 180
90 150
BLOWER OFF-DELAY
PLT
1
CO
OL H
EAT
SPARE-1 SPARE-2FAN
EAC-1
1-AMP@
115VAC PR-1
L1
PL2 1
24-V THERMOSTATTERMINALS
3-AMP FUSE
LED OPERATION &DIAGNOSTIC LIGHT
115-VAC(L2)NEUTRALCONNECTIONS
COOLHEAT
SPARE-1
SPARE-2 FANBLOWER SPEED
SELECTION TERMINALS
EAC-1 TERMINAL(115-VAC 1.0 AMP MAX.)
115 VAC (L1) LINEVOLTAGE CONNECTION
PL2-HOT SURFACEIGNITER & INDUCERMOTOR CONNECTOR
PL1-LOW VOLTAGE MAINHARNESS CONNECTOR
TRANSFORMER 24-VACCONNECTIONS
HUMIDIFIER TERMINAL(24-VAC 0.5 AMP MAX.)
TWINNING AND/ORCOMPONENT TEST
TERMINALBLOWER OFF-DELAY
A02142
Fig. 18 -- Single--Stage Furnace Control
PROCEDURE 8 — SEQUENCE OFOPERATION
See Fig. 15, 16, or 17 and 20 or 21 for single--speednon--condensing furnace twinning connection and schematicwiring diagrams while reviewing the sequence of operation.
Twinning operation is controlled by LH furnace. The TWIN/TESTand COM 24v connection wires ensure the 2 furnaces coordinatetheir blower operation. When either furnace requires bloweroperation, both furnaces operate their blowers at the same speed.Both furnaces operate simultaneously in the same mode: heat, cool,or continuous fan. Exceptions can occur if a safety switch on either
furnace is activated (such as pressure switch, flame roll--out switch,main limit switch, draft safeguard switch, twinning kit auxiliarylimit switch, or flame--proving sensor). In such a case, the otherfurnace continues to operate unless open switch is the flameroll--out, main limit, or twinning kit auxiliary limit switch, in whichcase both furnaces respond.
Before performing component test, disconnect TKR yellow wirelabeled TEST from LH furnace control TEST/TWIN terminal.After removing yellow wire, component test can be initiated oneach furnace individually as stated in Installation, Start--Up, andOperating Instructions.
KGATW
21
LHTOFFDLY
ON
OF
FW2
BLW
24-V-THERMOSTAT TERMINALS
SETUP SWITCHESLOW-HEAT ONLY ANDBLOWER OFF-DELAY
TWINNING AND/ORCOMPONENT TEST
TERMINALACRDJ - AIR CONDITIONING
RELAY DISABLE JUMPER
TRANSFORMER 24-VACCONNECTIONS
PL1 - LOW VOLTAGE MAINHARNESS CONNECTOR
PL3
HUMIDIFIER TERMINAL(24-VAC 0.5 AMP MAX.)
3-AMP FUSE
LED OPERATION &DIAGNOSTIC LIGHT
115-VAC (L2) NEUTRALCONNECTIONS
PL2 - HOT SURFACEIGNITER & INDUCERMOTOR CONNECTOR
115-VAC (L1) LINEVOLTAGE CONNECTION
EAC-1 TERMINAL(115-VAC 1.0 AMP MAX.)
BLOWER SPEEDSELECTION TERMINALS
HI HEATLO HEAT
SPARE-1
SPARE-2 COOL
Y1DHUM
GCO
M24V
WW
1Y/Y2
R
TEST/TWIN
HUM
1 2 3
PLT
AC
RD
J
0.5-AMP024 VAC
FUSE 3-AMP
SEC-1 SEC-2
PL1
NEUTRAL-L2
1
EAC-2
BHT/CLRBHI/LORPL3 1
BLWR
COOL
SPARE-1 SPARE-2
1-AMP@115 VAC
EAC-1 PR-1
IDR
HSIR
IDM
IHI/LOR
PL21
HSI HI LO
STATUS
CODELE
D
HI HEATLO
HEAT
L1
A02017
Fig. 19 -- Two--Stage Furnace Control
Single--Stage Heat with Single--Stage Gas--Heat ThermostatSee Section I, Procedure 2 for furnace and kit components used.
1. Single--stage thermostat causes both furnaces to operate inheating mode.
2. Operation in ALL modes is the same for twinned furnacesas for an individual furnace. See furnace Installation, Start--Up, and Operating Instructions for more information on se-quence of operation.
Two--Stage Heat with 2--Stage Gas--Heat ThermostatSee Section I, Procedure 2 for furnace and kit components used.
1. The 2--stage thermostat causes the furnaces to operate infirst--stage heat (LH furnace operates in heat while RH fur-nace blower operates but RH furnace is not heating) orcauses the furnaces to operate in second--stage heat (bothfurnaces operate in heat), depending on whether 1 or 2 ther-mostat stages are calling for heat.
2. Operation in ALL modes is the same for twinned furnacesas for an individual furnace. See furnace Installation, Start--Up, and Operating Instructions for more information on se-quence of operation.
SECTION II: SINGLE--SPEED AND TWO--SPEED MULTIPOISE CONDENSING HSIFURNACE MODELS
SINGLE STAGE TWO---STAGEModel Series Model Series Model Series58MCA 170 and later series 340MAV H and later series 58MTA 110 and later series58MXA 160 and later series 350MAV G and later series 58MTB 100 and later series58MCB 100 and later series PG9MAA E and later series 352MAV B and later series58MXB 100 and later series 340AAV A and later series 352AAV A and later series
58MSA 140 and later series 350AAV A and later series
345MAV E and later series PG9MAB A and later series
KGATW
22
PC
BY
1 R
Y/Y
2
WC
HU
M
EAC
-2
JB
L E G E N D
LS 1
, 2LI
MIT
SW
ITCH
, AU
TO-R
ESET
, SPS
T(N
.C.)
OL
AU
TO-R
ESET
INTE
RNA
L M
OTO
R O
VER
LOA
D
TEM
PERA
TURE
SW
ITC
H (
N.C
.)PC
BPR
INTE
D C
IRC
UIT
BOA
RD C
ON
TRO
LPL
111
-CIR
CUI
T PC
B C
ON
NEC
TOR
PL2
2-C
IRC
UIT
CO
NN
ECTO
RPL
32-
CIR
CU
IT H
SI,
CO
NN
ECTO
RPR
SPR
ESSU
RE S
WITC
H, S
PST-
(N.O
.)TE
ST/T
WIN
CO
MPO
NEN
T TE
ST &
TW
IN T
ERM
INA
LTR
AN
TRA
NSF
ORM
ER-1
15VA
C/2
4VA
C
JUN
CTIO
N
UNM
ARK
ED T
ERM
INA
L
PCB
CO
NTR
OL
TERM
INA
L
FAC
TORY
WIR
ING
(115
VAC
)
FAC
TORY
WIR
ING
(24V
AC
)
FIEL
D W
IRIN
G (
115V
AC
)
FIEL
D W
IRIN
G (2
4VA
C)
CO
ND
UC
TOR
ON
CO
NTR
OL
PCB
FIEL
D W
IRIN
G S
CRE
W T
ERM
INA
L
FIEL
D E
ART
H G
ROU
ND
EQUI
PMEN
T G
ROU
ND
FIEL
D S
PLIC
E
PLU
G R
ECEP
TAC
LE
L1
L1 BLW
RBH
T/C
LR
TO 1
15VA
C F
IELD
DIS
CO
NN
ECT
SWIT
CH
EQU
IPM
EN
T G
RO
UN
D
SPA
RE-
1
HEA
T
FAN
CO
OL
STA
RT
OL
HI
ME
D H
IM
ED L
OLO
BLW
M
SCH
EMAT
IC D
IAG
RAM
(NAT
UR
AL &
PR
OPA
NE
GAS
ES)
1H
SI
2PL
3
CAP
L2
NO
TES:
327560-101 REV. D
om
NEU
TRAL
L2
ILK
FU2
L1
ILK
RED
BLU
OR
N
GRN/YEL
TES
T/TW
IN
24V
FU1
LED
12345678910
J1
BLO
WE
R O
FF-D
ELA
Y
JUM
PE
R S
ELE
CT
OR
YEL
OL
STA
RT
BLK
WH
TW
HT
(C
OM
)
BLK
BLK
WH
TW
HT
21
PL2
BLW
M
CA
P
SPA
RE
1S
PAR
E 2
EAC
-1P
R1
L1
SE
C-2
SE
C-1
EAC
-2
180
150
120
90
PL1
BR
N
BR
N
RE
D (L
O)
WH
T(C
OM
)
YE
L
BLU
(ME
D L
O)
CO
M
G
DH
UM
BLK
(HI)
(ME
D H
I)
115V
ACPR
1
TRA
N
24V
AC
FRS1
FRS2
LGPS
PRS
FSE
IDM
DSS
BVSS
LS1
NO
TE #
10
(WH
EN
US
ED
)
F U
1N
OTE
#6
R W
SEC
-1SE
C-2
HU
MG
VR-2
PL1-
1
CP
U
Y1 G C
GV
R-1
OM
DH
UM
Y/Y
2
1.If
any
of th
e or
igin
al e
quip
men
t wire
is re
plac
ed u
se w
ire ra
ted
for 1
05°C
.2.
Use
onl
y co
pper
wire
bet
wee
n th
e di
scon
nect
sw
itch
and
the
furn
ace
junc
tion
box
(JB)
.3.
This
wire
mus
t be
conn
ecte
d to
furn
ace
shee
t met
al fo
r con
trol t
o pr
ove
flam
e.4.
Sym
bols
are
ele
ctric
al re
pres
enta
tion
only
.5.
Solid
line
s in
side
PC
B ar
e pr
inte
d ci
rcui
t boa
rd c
ondu
ctor
s an
d ar
e no
t inc
lude
d in
lege
nd.
6.R
epla
ce o
nly
with
a 3
am
p fu
se.
7.In
duce
r (ID
M) a
nd b
low
er (B
LWM
) mot
ors
cont
ain
inte
rnal
aut
o-re
set t
herm
al o
verlo
ad s
witc
hes
(OL)
.8.
Neu
tral c
onne
ctio
ns a
re in
terc
hang
eabl
e w
ithin
the
NEU
TRAL
con
nect
or b
lock
.9.
Blow
er m
otor
spe
ed s
elec
tions
are
for a
vera
ge c
ondi
tions
, see
inst
alla
tion
inst
ruct
ions
for d
etai
ls o
nop
timum
spe
ed s
elec
tion.
10.
Fact
ory
conn
ecte
d w
hen
BVSS
(C
him
ney
Adap
ter A
cces
sory
Kit)
is n
ot in
stal
led.
11.
Fact
ory
conn
ecte
d w
hen
LGPS
is n
ot u
sed.
12.
Igni
tion-
lock
out w
ill oc
cur a
fter f
our c
onse
cutiv
e un
succ
essf
ul tr
ials
-for-i
gniti
on. C
ontro
l will
auto
-rese
taf
ter t
hree
hou
rs.
13.
Blow
er-o
n de
lay:
gas
hea
ting
25 s
econ
ds, c
oolin
g or
hea
t pum
p 2
seco
nds.
14.
Blow
er-o
ff de
lay:
gas
hea
ting
sele
ctio
ns a
re 9
0, 1
20, 1
50 o
r 180
sec
onds
, coo
ling
or h
eat p
ump
90 s
econ
ds o
r 5 s
econ
ds w
hen
DH
UM
is O
N.
15.
YELL
OW
lead
not
on
all m
otor
s.
FAN
BFANR
TRAN
FSE
LS1
RE
D
RE
D
BLU
RE
DW
HT
BLK
BLK
WH
T
IDM
HSI
WH
T
BLK
21P
L3
FRS
1
FRS2
BV
SS
DS
S
11
EAC
-1H
SIR
1 2P
L2
IDR
FUS
E O
R C
IRC
UIT
BR
EA
KE
R &
DIS
CO
NN
EC
T S
WIT
CH
(WH
EN
RE
Q’D
)N
OTE
#2
GR
N/Y
EL
GR
N/Y
EL
GN
D
NO
TE #
3
NO
TE #
6
WH
T
NO
TE #
5
GV
GR
N/Y
EL
RE
D
24V
NO
TE #
11
PR
S(W
HE
N U
SE
D)
LGP
S
YE
L
(WH
EN
US
ED
)
NO
TE #
10
L2
(WH
EN
US
ED
)
NEUTRAL
NO
TE #
11
GV
NEUTRAL
NOTE #8
BFA
NR
CO
NTI
NUO
US-
FAN
SEL
ECT
RELA
Y, S
PDT
BHT/
CLR
BLO
WER
MO
TOR
SPEE
D C
HA
NG
E RE
LAY,
SPD
TBL
WR
BLO
WER
MO
TOR
RELA
Y, S
PST-
(N.O
.)BL
WM
BLO
WER
MO
TOR,
PER
MA
NEN
T-SP
LIT-
CA
PAC
ITOR
BVSS
BLO
CKE
D V
ENT
SHUT
OFF
SW
ITCH
, MA
NU
AL-
RESE
T, SP
ST -(
N.C
.)C
AP
CA
PAC
ITOR
CPU
MIC
ROPR
OC
ESSO
R A
ND
CIR
CUI
TRY
DSS
DRA
FT S
AFE
GU
ARD
SW
ITC
H, A
UTO
-RES
ET, S
PST
-(N
.C.)
EAC
-1EL
ECTR
ON
IC A
IR C
LEA
NER
CO
NN
ECTIO
N (1
15 V
AC
1.0
AM
P M
AX.
)EA
C-2
ELEC
TRO
NIC
AIR
CLE
AN
ER C
ON
NEC
TION
(CO
MM
ON
)FR
S 1,
2FL
AM
E RO
LLO
UT S
W. -
MA
NU
AL
RESE
T, SP
ST-(
N.C
.)FS
EFL
AM
E-PR
OV
ING
ELE
CTR
OD
EFU
1FU
SE, 3
AM
P, A
UTO
MO
TIVE
BLA
DE
TYPE
, FA
CTO
RY IN
STA
LLED
FU 2
FUSE
OR
CIR
CUI
T BR
EAKE
R C
URRE
NT
INTE
RRUP
T D
EVIC
E(F
IELD
INST
ALL
ED &
SU
PPLI
ED)
GN
DEQ
UIPM
ENT
GRO
UND
GV
GA
S VA
LVE-
RED
UN
DA
NT
GV
R 1,
2G
AS
VALV
E RE
LAY,
DPS
T-(N
.O.)
HSI
HO
T SU
RFA
CE
IGN
ITER
(115
VA
C)
HSI
RH
OT
SURF
AC
E IG
NITE
R RE
LAY,
SPS
T-(N
.O.)
HU
M24
VAC
HUM
IDIF
IER
CO
NN
ECTI
ON
(0.5
AM
P. M
AX.
)ID
MIN
DUC
ED D
RAFT
MO
TOR,
SH
AD
ED-P
OLE
IDR
IND
UCED
DRA
FT M
OTO
R RE
LAY,
SPS
T-(N
.O.)
ILK
BLO
WER
AC
CES
S PA
NEL
INTE
RLO
CK
SWIT
CH
, SPS
T-(N
.O.)
J1BL
OW
ER -
OFF
DEL
AY J
UMPE
R SE
LEC
TOR
JBJU
NC
TIO
N B
OX
LED
LIG
HT-
EMITT
ING
DIO
DE
FOR
STA
TUS
CO
DES
- A
MBE
RLG
PSLO
W G
AS
PRES
SURE
SW
ITCH
, SPS
T-(N
.O.)
NEU
TRAL
BH
T/C
LRB
FAN
RB
LWR
CO
NN
ECTI
ON
DIA
GR
AM
CO
OL
HE
AT
PL1-
6
PL1-
2
PL1-
4
PL1-
10
PL1-
5
PL1-
8
TES
T/TW
IN
PCB
NO
TE #
5
BLW
PRINTED CIRCIUT BOARD
PRINTED CIRCIUT BOARD
PL1-
3
PL1-
9PL
1-11
PL1
-7
NO
TE #
15
NO
TE #
15
LS2
(WH
EN
US
ED
)
LS2
(WH
EN
US
ED
)
RE
DR
ED
RE
D
RE
DO
RG
OR
G
A02140
Fig. 20 -- Wiring Diagram for Fixed--Capacity, Non--Condensing Furnaces
KGATW
23
GV
HIM
GR
N/Y
EL
CN
OTE
#3
BRN
BLU
BRN
GR
N/Y
EL
RED
RED
RED
NO
TE #
11FR
S1D
SS
BVS
S
LS1
(WH
EN U
SED
)
FRS2
NO
TE #
12
OR
NYE
L
HSI
L1N
OTE
#2
GN
D
NEU
TRAL
FU2
FUSE
OR
CIR
CUI
TBR
EAKE
R &
DIS
CO
NN
ECT
SWITC
H (W
HEN
REQ
'D)
BLK
ILK
PL5
JB
1 2
SEC-1
LEDSEC-2
FUSE 3-AMPPL
T
AC
RD
J
0.5 AMP@ 24 VAC
HUM
TEST/TWIN
ON
OFF
32
1
DLYOFFLHT
W/W
1D
HU
MG
24Vom
CW
2Y
/Y2
RY
1
TRAN
L1
PR-1
EAC-1
CA
P
OL
SPARE - 1
BLWR BHT/CLR BHI/LOR
COOL LO-HEAT
HI-HEAT
STA
RT
GR
N/Y
EL
BLW
M
NEUTRAL - L2 EAC-2R
ED
BLU
OR
NYE
LBL
K
LOM
ED L
OM
EDHI
MED
HI
RED
BLU
WH
TW
HT
BRN
BRN
BLK
WH
T
BLK
WH
T
IHI/L
OR
HSI
R
IDR
LO HI HSI
GR
Y
CO
NN
ECTI
ON
DIA
GR
AM
BLK
1H
SI
2
IDM
1 23
HI
CO
M LO
S
CH
EMAT
IC D
IAG
RAM
(NAT
UR
AL G
AS &
PR
OPA
NE)
IDR
T
O 1
15VA
C F
IELD
-DIS
CO
NN
ECT
SWIT
CH
EQU
IPM
ENT
GR
OU
ND
12 3H
SIR
IHI/L
OR
PL2
L2
L2
CAP
OL
STAR
T
BLW
M
CO
M
LOM
ED L
OM
ED HI
ME
D H
I
LO H
EAT
SPA
RE-
2C
OO
LIN
G
SPAR
E-1
BHI/L
OR
BHT/
CLR
BLW
R
EAC
-2EA
C-1
TRAN
L2
L2
115V
AC
24VA
CSE
C 2
SEC
1
PR
1
FU1
NO
TE #
6
FRS
1D
SS
BVSS
FRS
2
(WH
EN U
SED
)
PL1-
8G
VR
-2H
UM R
AC
RPL
1-12
HP
SR
GV
LPS
NO
TE #
12
LGP
S(W
HEN
USE
D)
HPS HI
PL1-
2
PL1-
4
PL1-
3
PL1-
10
PL1-
5
W/W
1
CP
U
GVR
-1
TEST
/TW
IN
DH
UM
W2
Y/Y2
G Y1 CO
M 2
4VN
OTE
#3 CM
PL1-
1
LPS
(WH
EN
US
ED
)LG
PS
WH
T
FSE
PL1-
9
PL1-
11
PL1-
7
LEG
EN
D
AC
RA
IR C
ON
DITI
ON
ING
REL
AY, S
PST
(N.O
.)A
CRD
JA
IR C
ON
DITI
ON
ING
REL
AY D
ISA
BLE
JUM
PER
BHI/L
OR
BLO
WER
MO
TOR
SPEE
D C
HA
NG
E RE
LAY,
SPD
TBH
T/C
LRBL
OW
ER M
OTO
R SP
EED
CH
AN
GE
RELA
Y, S
PDT
BLW
RBL
OW
ER M
OTO
R RE
LAY,
SPS
T-(N
.O.)
BLW
MBL
OW
ER M
OTO
R, P
ERM
AN
ENT-
SPLI
T-C
APA
CITO
RBV
SSBL
OC
KED
VEN
T SH
UTO
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WITC
H, M
AN
UAL-
RESE
T, SP
ST -(
N.C
.)C
AP
CA
PAC
ITO
RC
PUM
ICRO
PRO
CES
SOR
AN
D C
IRC
UITR
YD
HUM
DH
UM C
ON
NEC
TION
D
SSD
RAFT
SA
FE G
UARD
SW
ITCH
, AUT
O-R
ESET
, SPS
T -(
N.C
.)EA
C-1
ELEC
TRO
NIC
AIR
CLE
AN
ER C
ON
NEC
TION
(115
VA
C 1
.0 A
MP
MA
X.)
EAC
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ECTR
ON
IC A
IR C
LEA
NER
CO
NN
ECTIO
N (C
OM
MO
N)
FRS
1, 2
FLA
ME
ROLL
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T SW
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AN
UAL
RESE
T, SP
ST-(
N.C
.)FS
EFL
AM
E-PR
OV
ING
ELE
CTR
OD
EFU
1FU
SE, 3
AM
P, A
UTO
MO
TIVE
BLA
DE
TYPE
, FA
CTO
RY IN
STA
LLED
FU2
FU
SE O
R C
IRC
UIT
BREA
KER
CU
RREN
T IN
TERR
UPT
DEV
ICE
(FIE
LD S
UPPL
IED
AN
D IN
STA
LLED
)G
ND
EQU
IPM
ENT
GRO
UND
GV
GA
S VA
LVE-
RED
UND
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T G
VR
1, 2
GA
S VA
LVE
RELA
Y, D
PST-
(N.O
.)H
PSH
IGH
-HEA
T PR
ESSU
RE S
WITC
H, S
PST
(N.O
.)H
PSR
HIG
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EAT
PRES
SURE
SW
ITCH
REL
AY, S
PST
(N.C
.)H
SIH
OT
SURF
AC
E IG
NIT
ER (1
15VA
C)
HSI
RH
OT
SURF
AC
E IG
NIT
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ELAY
, SPS
T (N
.O.)
HUM
24VA
C H
UM
IDIF
IER
CO
NN
ECTIO
N (0
.5 A
MP.
MA
X.)
IDM
IND
UC
ED D
RAFT
MO
TOR,
SH
AD
ED-P
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IDR
IND
UC
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RAFT
MO
TOR
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(N.O
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SPEE
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E RE
LAY,
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ER A
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ESS
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EL IN
TERL
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K SW
ITCH
, SPS
T-(N
.O.)
JBJU
NC
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BO
XLE
DLI
GH
T-EM
ITTIN
G D
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E FO
R ST
ATU
S C
OD
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AM
BER
LGPS
LOW
GA
S PR
ESSU
RE S
WIT
CH
, SPS
T-(N
.O.)
LPS
LOW
-HEA
T PR
ESSU
RE S
WITC
H, S
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(N.O
.)LS
1, 2
LIM
IT S
WIT
CH
, AU
TO-R
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, SPS
T (N
.C.)
OL
AU
TO-R
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INTE
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L M
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R O
VER
LOA
D T
EMPE
RATU
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WITC
H (N
.C.)
PCB
PRIN
TED
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IT BO
ARD
CO
NTR
OL
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12-C
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PCB
CO
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(NO
T SH
OW
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PL4
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IDM
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52-
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FAC
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, 115
VAC
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TEST
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INC
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TEST
& T
WIN
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UNM
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FAC
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(115
VAC
)
FAC
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CO
NTR
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WIR
ING
(24V
AC
)
FIEL
D C
ON
TRO
L W
IRIN
G (1
15VA
C)
FIEL
D C
ON
TRO
L W
IRIN
G (2
4VA
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CO
ND
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TOR
ON
CO
NTR
OL
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ND
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6
L1
NO
TE #
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L2
PL4
PL5
WH
T
GR
N/Y
EL
WH
T
RED BLK
IDM
CO
MLO
PL4 13 2
H I
WH
T
RED BLK
PL2
IDM
NOTE #8
1 AMP @ 115 VAC
STA
TUS
CO
DE
FU1NOTE #6
PL1
1
SELE
CT
CH
ART
SWLO
-HT
ON
LYB
LOW
ERO
FF-D
ELA
Y
ON
OFF
1
ON
LYH
EAT
LOHEA
TN
OR
M2
390 SE
C.
ON
OFF
12
312
0SE
C.
ON
OFF
23
150
SEC
.
ON
OFF
23
180
SEC
.
HP
S
FAC
TOR
Y S
ETTI
NG
S
BLW
HI H
EAT
NO
TE #
11
NO
TE #
5
*
*
*
SPARE-2
FSE
RED
ACRDJ
3275
61-1
01 R
EV
. E
1.If
any
of th
e or
igin
al e
quip
men
t wire
is re
plac
ed u
se w
ire ra
ted
for 1
05∞C
.2.
Use
onl
y co
pper
wire
bet
wee
n th
e di
scon
nect
sw
itch
and
the
furn
ace
junc
tion
box
(JB
).3.
This
wire
mus
t be
conn
ecte
d to
furn
ace
shee
t met
al fo
r con
trol
to p
rove
flam
e.4.
Sym
bols
are
ele
ctric
al re
pres
enta
tion
only
.5.
Solid
line
s in
side
PC
B a
re p
rinte
d ci
rcui
t boa
rd c
ondu
ctor
s an
d ar
e no
t inc
lude
d in
the
lege
nd.
6.R
epla
ce o
nly
with
a 3
am
p fu
se.
7.B
low
er m
otor
(BLW
M) a
nd in
duce
r mot
or (I
DM
) con
tain
inte
rnal
aut
o-re
set t
herm
al o
verlo
ad s
witc
hes
(OL)
.8.
Neu
tral
con
nect
ions
are
inte
rcha
ngea
ble
with
in th
e N
EUTR
AL
conn
ecto
r blo
ck.
9.B
low
er m
otor
spe
ed s
elec
tions
are
for a
vera
ge c
ondi
tions
, see
inst
alla
tion
inst
ruct
ions
for o
ptim
um s
elec
tion.
10.F
acto
ry s
hipp
ed w
ith B
LUE
wire
(MED
LO
) if O
RA
NG
E w
ire n
ot p
rese
nt.
11.F
acto
ry c
onne
cted
whe
n B
VSS
(Chi
mne
y A
dapt
er K
it) is
not
inst
alle
d.12
.Fac
tory
con
nect
ed w
hen
LGPS
is n
ot u
sed.
13.I
gniti
on lo
ckou
t will
occ
ur a
fter f
our c
onse
cutiv
e un
succ
essf
ul tr
ials
-for-
igni
tion.
Con
trol
will
aut
o-re
set a
fter
thre
e ho
urs.
14.B
low
er-o
n de
lay:
gas
hig
h-he
at 2
5 se
cond
s, g
as lo
w-h
eat 4
5 se
cond
s, c
oolin
g or
hea
t pum
p 2
seco
nds.
15.B
low
er o
ff-de
lay:
gas
hea
ting
sele
ctio
ns a
re 9
0, 1
20, 1
50, 1
80 s
econ
ds, c
oolin
g or
hea
t pum
p 90
sec
onds
or
5 se
cond
s w
hen
DH
UM
is a
ctiv
e.
NO
TE
S:
PRINTED CIRCIUT BOARD
PRINTED CIRCIUT BOARD
RED
LS2
(WH
EN U
SED
)
LS2
(WH
EN
USE
D)
LS1
ILK
L1
A02159
Fig. 21 -- Wiring Diagram for Two--Stage, Non--Condensing Furnaces
KGATW
24
17 5/16″
24 1/2″
27 1/2″TYP
27 5/8″
29 5/8″TYP
30 13/16″TYP
32 5/8″TYP
33 1/4″TYP
CONDENSATE DRAINTRAP LOCATION
7/8-IN. DIAACCESSORYPOWER ENTRY
7/8-IN. DIAPOWER CONN
26 15/16″
24 1/2″22 1/4″
2-IN. COMBUSTION-AIR CONN
1/2-IN. GAS CONN
2-IN. VENT CONN
1/2-IN. DIA THERMOSTATENTRY
22 11/16″
SIDE INLET
23 1/4″
11/4″1" E
INLET
11/16″E
INLET
11/16″
F 13/16″13/16″
OUTLET
A
AIRFLOW
OUTLET
26 15/16″28 1/2″
26 1/4″
22 13/16″19″ 13/16″
5/8″
39 7/8″
11/16″24 3/16″BOTTOM INLET
18 1/4″
22 11/16″
2-IN. COMBUSTION-AIR CONN
1/2-IN. GAS CONN
7/8-IN. DIAPOWER CONN
1/2-IN. DIATHERMOSTAT ENTRY
2-IN. VENT CONN
14 1/2″ SIDE INLET
OUTLET
AIRFLOW
D D
9 3/8″TYP
26 15/16″ TYP
SIDE INLET
CONDENSATEDRAIN LOCATION(USED FOR LH FURNACES AFTERSERIAL NO. 2894A00001)
30 1/2″
CONDENSATEDRAIN LOCATION(USED FOR RH FURNACES AFTERSERIAL NO. 2894A00001)
CONDENSATE DRAIN TRAP LOCATION
(USED FOR RH FURNACES BEFORESERIAL NO. 2894A00001)
(USED FOR LH FURNACES BEFORE SERIAL NO.
2894A00001)
26 1/4 TYP
A93537
Fig. 22 -- Dimensional Drawing for Twinned Single--Speed Condensing Furnaces (Upflow, Downflow)
Table 3 – 58MCA, 58MCB, 58MSA, 58MTB, 58MXA, 58MXB, 58MTZ, 340AAV, 340MAV, 345MAV, 350AAV, 350MAV, 352AAV,352MAV, 490AAV, PG9MAA and PG9MAB
Single--Speed Condensing Furnace Dimensions -- In. (mm)INPUT HEATING SIZE
(BTUH) NOMINAL COOLING SIZE A D E F
60,000 48,000 35 (889) 15---7/8 (403) 16 (406) 33---3/8 (848)80,000* 48,000 35 (889) 15---7/8 (403) 16 (406) 33---3/8 (848)80,000 60,000 42 (1067) 19---3/8 (492) 19---1/2 (495) 40---3/8 (1026)100,000* 48,000 42 (1067) 19---3/8 (492) 19---1/2 (495) 40---3/8 (1026)100,000* 60,000 42 (1067) 19---3/8 (492) 19---1/2 (495) 40---3/8 (1026)120,000* 60,000 49 (1245) 22---7/8 (581) 23 (584) 47---3/8 (1203)
*Two---speed furnace capacities and dimensions
PROCEDURE 1 — INSTALL FURNACES
NOTE: Multipoise units can be installed in UPFLOW,DOWNFLOW, or HORIZONTAL configurations.
A. Upflow, Downflow, Side--By--Side ConfigurationRefer to Fig. 22 for appearance and dimensional drawing oftwinned furnaces and their connection locations.
1. Select 2 identical heating and airflow furnaces. (See Table3.)
2. Remove bottom closure panels from both furnaces. (SeeFig. 21.)
a. Remove main and blower access doors.
b. Remove 2 screws from front filler panel.
c. Rotate front filler panel downward to remove.
d. Remove bottom closure panel and discard.
e. Reinstall front filler panel.
3. Apply 2 factory--supplied foam strips to mating side of eachfurnace. Locate strips equal distance from top and bottom asshown in Fig. 25.
4. Return air connections
a. For upflow applications: Bottom return air usage is re-quired as part of any upflow return air configuration. Ifadditional return air is to enter 1 side of each furnace, inaddition to bottom return air, cut open 1 entire return--air opening in appropriate side of each furnace. (SeeFig. 1.)
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit damage, fire,personal injury or death.
DO NOT use the back of the furnace for return--air ductconnections as limit cycling will occur.
! WARNING
b. For downflow applications: Return air can only be con-nected to bottom opening of furnace. A common returnair plenum is required for proper auxiliary limit switchoperation. (See Fig. 2.)
5. For upflow applications
a. Position furnaces against each other on return--air plen-um. Adjust and shim each furnace to align unused con-densate drain line holes in lower section of both fur-naces holes, which will be used for wire routingbetween furnaces. (See Fig. 31.)
b. Drill two 1/8--in. holes, approximately 1 in. (25 mm)be-low discharge air flange, from inside top of dischargeopening and through both furnaces. (See Fig. 26.)
c. Drive 1 factory--supplied No. 6 X 3/4--in. LG screwthrough each hole and tighten until furnaces are secureand foam strips have sealed gap between furnaces.
KGATW
25
A02234
Fig. 23 -- Back--to--Back (Upflow, Downflow or Horizontal)
Table 4 – Dimensions -- In. (mm)
INPUT HEATING SIZE(BTUH)
NOMINALCOOLINGSIZE
A D ETWINNED FURNACE
WEIGHTLBS (kg)
60,000 48,000 17–1/2 (445) 15---7/8(403) 16 (406) 350 (159)
80,000* 48,000 17–1/2 (445) 15---7/8(403) 16 (406) 410 (186)
80,000 60,000 21 (533) 19---3/8 (492) 19---1/2 (495) 228 (103)100,000* 48,000 21 (533) 19---3/8 (492) 19---1/2 (495) 458 (208)100,000* 60,000 21 (533) 19---3/8 (492) 19---1/2 (495) 464 (210)120,000* 60,000 24–1/2 (622) 22–7/8 (581) 23 (584) 522 (237)
*Two---Speed furnace capacities and dimensions
BOTTOMCLOSUREPANEL
FRONT FILLERPANEL
A93047
Fig. 24 -- Bottom Closure Panel
FOAMSTRIPS
UNUSED CONDENSATEDRAIN HOLE
FOR BACK-TO-BACKAPPLICATIONS, APPLYFOAM STRIPS AT THISHEIGHT, ALONG BACK OF FURNACE
A02236
Fig. 25 -- Location of Foam Strips and Hole to be used forTwinning Kit Wire Routing
KGATW
26
SCREW DISCHARGEOPENINGS TOGETHER
A93539
Fig. 26 -- Attaching Furnaces Together
6. For downflow applications:
a. Position furnaces on downflow kits (no A/C coils) or onentering air--side of A/C coils. Adjust and shim eachfurnace to align unused condensate drain line holes inlower section of both furnaces holes, which will be usedfor wire routing between furnaces. (Similar to Fig. 31.)
b. Drill two 1/8--in. holes, approximately 1 in. (25 mm)be-low return air flange, from inside top of return air open-ing and through both furnaces. (See Fig. 27.)
c. Drive 1 factory--supplied No. 6 X 3/4--in. LG screwthrough each hole and tighten until furnaces are secureand foam strips have sealed gap between furnaces.
7. Insert 1 snap bushing through each adjoining unused con-densate drain line hole of each furnace.
8. Connect return-- and supply--air ducts to furnaces. Seal ductconnections to prevent air leakage.
9. 115--V junction boxes JB must be located on right side ofright--hand furnace and left side of left--hand furnace. Relo-cate as necessary. (See Fig. 31.)
10. Follow individual furnace installation instructions for up-flow/downflow applications. This includes, but not limitedto: condensate trap, condensate/inducer housing tubing,pressure switch tubing venting and electrical connections.
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit damage, fire,personal injury or death.
DO NOT use the back of the furnace for return--air ductconnections as limit cycling will occur.
! WARNING
B. Upflow/Downflow, Back--to--Back ConfigurationRefer to Fig. 23 and Table 4 for appearance and dimensionaldrawing of twinned furnaces and their connection locations.
1. Select 2 identical heating and airflow furnaces. (See Table4.)
2. Remove bottom closure panels from both furnaces. (SeeFig. 24.)
a. Remove main and blower access doors.
b. Remove 2 screws from front filler panel.
A02219
Fig. 27 -- Attaching Furnaces Together -- Downflow
c. Rotate front filler panel downward to remove.
d. Remove bottom closure panel and discard.
e. Reinstall front filler panel.
3. Apply 2 factory--supplied foam strips to mating back ofeach furnace. Locate strips equal distance from top and bot-tom as shown in Fig. 25. Trim off excess material.
4. Return Air Connections
a. For upflow applications: Bottom return air usage is re-quired as part of any upflow return air configuration. Ifadditional return air is to enter 1 side of each furnace, inaddition to bottom return air, cut open 1 entire return--air opening in appropriate side of each furnace. (SeeFig. 1.)
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit damage, fire,personal injury or death.
DO NOT use the back of the furnace for return--air ductconnections in upflow position, as limit switch cycling willoccur.
! WARNING
b. For downflow applications: Return air can only be con-nected to bottom opening of furnace. A common returnair plenum is required for proper auxiliary limit switchoperation. (See Fig. 2.)
5. For upflow applications
a. Position furnaces against each other on return--air plen-um. (See Fig. 23.)
b. Drill two 1/8--in. holes, approximately 1 in. (25 mm)be-low discharge air flange, from inside top of dischargeopening and through both furnaces. (See Fig. 27.)
c. Drive 1 factory--supplied No. 6 X 3/4--in. LG screwthrough each hole and tighten until furnaces are secureand foam strips have sealed gap between furnaces.
6. For downflow applications
a. Position furnaces on downflow kits or plenum (no A/Ccoils) or on entering air--side of A/C coils. (See Fig. 23.)
b. Drill two 1/8--in. holes, approximately 1 in. (25 mm)be-low return air flange, from inside top of return air open-ing and through both furnaces. (See Fig. 27.)
KGATW
27
COMBUSTION – AIRINTAKE
VENT
MANUALSHUTOFF
GAS VALVE
SEDIMENTTRAP
CONDENSATETRAP
ACCESS OPENINGFOR TRAP
30 IN. (762 MM) MIN WORK AREA
A 12 IN. (305 MM) MIN HORIZONTAL PIPESECTION IS RECOMMENDED WITHSHORT (5 TO 8 FT / 1.5 TO 2.4 M) VENT SYSTEMS TO REDUCE EXCESSIVECONDENSATE DROPLETS FROMEXITING THE VENT PIPE.
5-3/4 IN. (146 MM)
COMMON RETURN
30 (762 MM) MINWORK AREA
EXTERNAL EXTENSIONTWINNING HARNESS
A02209
Fig. 28 -- Attic Installation on a Platform
c. Drive 1 factory--supplied No. 6 X 3/4--in. LG screwthrough each hole and tighten until furnaces are secureand foam strips have sealed gap between furnaces.
7. Determine which side of furnace will be used to route ex-ternal extension harness. If condensate drain hole is avail-able, use it, otherwise, drill two 7/8--in holes in blowerhousing area, mid--point between blower deck and bottomof furnace.
NOTE: The external extension harness cannot be used on thesame side of the furnace that the return air ducts connect to. Locateharness on opposite side of furnace where return air is used.
8. Connect return and supply--air ducts to furnaces. Seal ductconnections to prevent air leakage.
9. Follow individual furnace installation instructions for up-flow/downflow applications. This includes, but not limitedto: condensate trap, condensate/inducer housing tubing,pressure switch tubing venting and electrical connections.
C. Horizontal, Back--to--Back ConfigurationWhen twinning furnaces in the horizontal position, considerationmust be made to the type of building construction. Attic floorsshould be constructed to support normal live and dead loads of thefurnaces and the person(s) servicing them. Trusses, wood andmetal are engineered for specific applications, and may not supportthe weight of two (2) furnaces suspended from the top chords orthe bottom chords of the trusses. Long horizontals spans may flexor sag, resulting in damage to the building. Contact the trussmanufacturer for additional design and engineering assistance.
Do not suspend furnaces with straps or suspend furnaces from roofdecking.
For attic installations on a platform:
1. Construct a platform from 3/4--in. (nominal plywood), ex-tending out 30 inches (762 mm) from the front of each fur-nace. (See Fig. 28.)
2. Maintain all clearances to combustibles per the furnace In-stallation, Start--up and Operating Instructions.
3. Follow all additional building codes.
4. Long truss spans may require additional support along thebottom chord of the truss. Consult the truss manufacturer’sguidelines for engineering assistance.
5. Long rafter or attic joist spans may require additional sup-port along the bottom of the rafter or joist. Consult local orregional building codes for design and loading require-ments.
For suspended installations (Not recommended for wood trusses)(See Fig. 29.):
1. Furnaces may be suspended using two (2) pieces of1--1/2--in. x 1--1/2--in. x 1/4--in. thick cold rolled angle ironunderneath each furnace and four (4) 3/8--in. diameterthreaded rods.
2. Allow for at least 8 inches (203 mm) in front of each doorfor door removal.
3. Each piece of angle iron must be secured to the bottom ofeach furnace with at least two (2) #8 x �� sheet metalscrews.
4. Maintain all clearances to combustibles per the furnace In-stallation, Start--up and Operating Instructions.
5. Unistrut or similar material may be used, provided that thefurnaces do not sag in the middle or bend or twist at thesupport ends. The support material must be secured to thebottom of each furnace in a manner similar to securingangle iron to the furnace.
Refer to Fig. 23 and Table 4 for appearance and dimensionaldrawing of twinned furnaces and their connection locations.
1. Select 2 identical heating and airflow furnaces. (See Table4.)
2. Remove bottom closure panels from both furnaces. (SeeFig. 24.)
a. Remove main and blower access doors.
b. Remove 2 screws from front filler panel.
c. Rotate front filler panel downward to remove.
d. Remove bottom closure panel and discard.
e. Reinstall front filler panel.
KGATW
28
3/8" ROD, HEX NUT& WASHER
(B)(A)
(A)(B)
(B)
(A) ROD LOCATION USING� DIMPLE LOCATORS� ( SEE DIMENSIONAL DWG� FOR LOCATIONS)
(B)(A)
(A) PREFERRED ROD LOCATION�(B) ALTERNATE ROD LOCATION
11/2" ANGLE�OR EQUIVALENT
(B)(B)(A)
3/8" NUT, BOLT�& WASHERS
(A)(B)
USING (B) LOCATIONS�13/16" MAX FROM BACK �OF FURNACE
DRAIN
53/4"
USING (B) LOCATIONS�4" TO 8" MAX
3/8" ROD, HEX NUT& WASHER
(B)(A)
(A)(B)
(B)
(A) ROD LOCATION USING� DIMPLE LOCATORS� ( SEE DIMENSIONAL DWG� FOR LOCATIONS)
(B)(A)
(A) PREFERRED ROD LOCATION�(B) ALTERNATE ROD LOCATION
11/2" ANGLE�OR EQUIVALENT
(B)(B)(A)
3/8" NUT, BOLT�& WASHERS
(A)(B)
USING (B) LOCATIONS�13/16" MAX FROM BACK �OF FURNACE
DRAIN
53/4"
USING (B) LOCATIONS�4" TO 8" MAX
A02208
Fig. 29 -- Suspended Installation of Furnaces
3. Apply 2 factory--supplied foam strips to mating back ofeach furnace. Locate strips equal distance from top and bot-tom as shown in Fig. 25. Trim off excess material.
4. Securing furnaces together:
a. Lay furnaces back--to--back on a flat surface.
b. Similar to side--by--side installations (See Fig. 26.), drilltwo 1/8--in. holes, approximately 1 in. (25 mm)belowdischarge air flange, from inside top of discharge open-ing and through both furnaces. Also drill two 1/8--in.holes, approximately 1 in. (25 mm)below return airflange, from inside top of return air opening andthrough both furnaces.
c. Drive 1 factory--supplied No. 6 X 3/4--in. LG screwthrough each hole and tighten until furnaces are secureand foam strips have sealed gap between furnaces.
5. With furnaces laying in their side and back--to--back, de-termine which side will now be the top side to route extern-al extension harness. Use the unused condensate drain holesin blower housing area.
6. Connect return-- and supply--air ducts to furnaces. Seal ductconnections to prevent air leakage.
7. Follow individual furnace installation instructions for hori-zontal applications. This includes, but not limited to: con-densate trap, condensate/inducer housing tubing, pressureswitch tubing venting and electrical connections.
PROCEDURE 2 — CONNECT ELECTRICALCOMPONENTS—HEATING
FIRE HAZARD
Failure to follow this warning could result in fire, personalinjury or death.
Make no connections between the R 24--vac connector in 1furnace and the R 24--vac connector in other furnace.
! WARNING
See Electrostatic Discharge Precaution Section.
NOTE: To determine referencing of Left Hand (LH) and RightHand (RH) furnace:
a. In the Side--by--Side, upflow and downflow applica-tions, reference the furnaces from the front, as youwould see them in the upflow application (See Fig. 31.)The LH furnace is the main furnace and the RH furnaceis the secondary furnace.
b. In the Back--to--Back, upflow, downflow and horizontalapplications, reference the furnaces from the side of theexternal extension harness. The LH furnace is the mainfurnace and the RH furnace is the secondary furnace, asyou would see them in the upflow application (See Fig.32.)
There are 3 harnesses included in this kit. If the furnaces areside--by--side, only 2 harnesses are required. If the furnaces areinstalled back--to--back, all 3 harnesses included in the kit must beused.
1. Remove outer doors and blower access doors from both fur-naces.
KGATW
29
A02226
Fig. 30 -- Twinning Kit Relay Mounted on Control MountingBracket for LH Furnace
2. If furnaces are installed back--to--back in any orientation, theExternal Extension Harness must be used. The harness con-sists of:
a. 54--1/2 inches (1384 mm) of 1/2--in. flexible steel con-duit
b. (2) 90_ conduit connectors
c. (3) 4 wire polarized wiring harness
d. (3) 2 wire polarized wiring harness
Install the harness as follows:
a. Remove lock nuts from the end of each conduit con-nector.
b. Route the end of the harness that mates to the TKR re-lay harness of the LH furnace through the unused con-densate trap hole in the casing of the blower compart-ment.
c. Route the end of the harness that mates to the 4--wireharness of the RH furnace through the unused condens-ate trap hole in the casing of the blower compartment.
d. Install the lock nuts on the 90_ conduit connectors.
e. Install the two kit--supplied straps approximately 18inches (457 mm) from each end of extension harness.
3. Fixed Capacity Furnace/Single--Stage Heat with Single--Stage Gas--Heat Thermostat (Field Supplied) OR Two--Stage Furnace with Single or Two--Stage Gas--Heat Ther-mostat (Field--Supplied)
NOTE: This application of TKR allows both furnaces to operateas 1 furnace gas heat mode as determined by an individualthermostat. Install twinning kit relay (TKR):
a. Mount TKR assembly to underside of LH furnace con-trol enclosure using 1 No. 6 sheet metal screw (factorysupplied). Screw hole is located to left of door switchnear front edge of control. (See Fig. 30.)
NOTE: See Fig. 15 or 17 for twinning kit wiring.
b. Route 3 loose wires (black, yellow, and white) fromTKR assembly wire harness through T--STAT/HUMhole adjacent to door switch. (See Fig. 30.)
c. Connect TKR white wire labeled W from TKR to LHfurnace control thermostat connection W or W/W1.
d. Connect TKR black wire labeled C from TKR to LHfurnace control thermostat connection COM 24V.
e. Connect yellow wire labeled TEST to LH furnace con-trol TEST/TWIN terminal.
f. Route female four--pin connector end of TKR wires:
(1.) For Side--by--Side applications, see Fig. 22 and31. Route female, four--pin connector through pre-viously installed bushings in unused condensatedrain holes, located on casing in blower compart-ment area. Connect to male four--pin connector ofRH furnace.
(2.) For Back--to--Back applications, see Fig. 23 and32. Connect the female, four pin connector to themale four pin connector of the previously installedExternal Extension Kit. Connect the female fourpin connector of the External Extension Kit to themale four pin connector of the RH furnace.
g. Route four wires through thermostat cable hole of RHfurnace control box.
h. Connect TKR red wire labeled R--SECONDARY fromTKR to RH furnace control thermostat connection R.
i. Connect TKR white wire labeled W--SECONDARYfrom TKR to RH furnace control thermostat connectionW or W/W1.
j. Connect TKR black wire labeled C--SECONDARYfrom TKR to RH furnace control thermostat connectionCOM 24V.
k. Connect yellow wire labeled TEST SECONDARY fromLH furnace control TEST/TWIN terminal to RH furnacecontrol TEST/TWIN terminal.
l. For Two--Stage Furnace Control Boards–In additionto the wiring of the twinning kit, the LHT switch and asingle OR two--stage gas--heat thermostat must be con-figured to one of the two methods describe below:Two--Stage Heat with Single--Stage Gas--Heat Ther-mostat (allows the LH or Main Furnace’s algorithmcontrol low and high--heat operation)(1.) Position LHT switch on Main or LH furnace con-
trol to OFF.
(2.) Position LHT switch on Secondary or RH furnacecontrol to ON.Two--Stage Heat with Two--Stage Gas--HeatThermostat (allows a two--stage thermostat tocontrol low and high--heat operation)Position LHT switch furnace controls in BOTHfurnaces to ON
m. Proceed to #5 “Install LH furnace auxiliary limit switchharness ALS--M” to complete electrical connections.
KGATW
30
AUXILIARY LIMITDOOR SWITCH(ILK-I)
POWER JUNCTION BOXRELOCATED HERE
SECONDARY AUXILIARYLIMIT SWITCH (ALS-S)
MAIN 24-VTRANSFORMER
MAIN BLOWER ACCESSPANEL DOOR SWITCH
SECONDARY 24-VTRANSFORMER
MAIN AUXILIARYLIMIT SWITCH
(ALS-M)
8″ TYP
TWINNING KITRELAY (TKR)
SECONDARY BLOWER ACCESSPANEL DOOR SWITCH
UNUSED CONDENSATEDRAIN LINE HOLESWITH SNAPBUSHING INSTALLED
A01377
Fig. 31 -- Twinning Kit Installed on Single--Speed and 2--Stage Condensing Furnaces (After Serial No. 2894A00001)Single--Speed Shown
Unused condensatedrain location
External Extension
A02225
Fig. 32 -- External Extension Harness(Back--to--Back Application)
4. Two--Stage Heating using Fixed--Capacity Furnaces withTwo--Stage Gas Heat Thermostat (Field Supplied). See Fig.16.
NOTE: This modification allows LH furnace only to operate inheating mode for first--stage heat or both furnaces to operate inheating mode for second--stage heat as determined by a 2--stagethermostat. See furnace Installation, Start--Up, and OperatingInstructions for further details on this heating mode.
To operate furnaces in 2--stage heating mode when a 2--stagethermostat controls the staging, install twinning kit as describedabove, then modify TKR wiring as follows:
PERSONAL INJURY HAZARD
Failure to follow this caution may result in intermittent furnaceoperation and unit damage.
Supply--air temperature will be uneven left--to--right whenonly main system is operating.
CAUTION!
KGATW
31
A02237
Fig. 33 -- LHT Switches
NOTE: See Fig. 16.
a. Disconnect TKR white wire labeled W from LH furnacecontrol thermostat connection W.
b. Cut terminal off TKR white wire labeled W and strip1/4 in. (6 mm).
c. Connect 2--stage thermostat W2 connection to TKRwhite wire labeled W.
NOTE: ALL other 2--stage thermostat connections are to be madeto LH furnace control center ONLY.
d. Proceed to #5 “Install LH furnace Auxiliary LimitSwitch -- Main ALS--M” harness to complete electricalconnections.
5. Install LH furnace (main) auxiliary limit switch harnessALS--M.
NOTE: LH furnace ALS--M assembly DOES NOT include doorswitch.
a. Drill 1/8--in. hole in blower housing 8 in. below blowershelf as shown in Fig. 31.
b. Position ALS--M so reset button faces front of furnace.
c. Secure bracket to blower housing using factory--sup-plied No. 6 X 3/4--in. LG screw.
d. Disconnect red transformer wire from SEC--1 connec-tion.
e. Connect removed red transformer wire to ALS--M wireconnector labeled TRAN. Route through thermostatholes of control box.
f. Connect ALS--M connector labeled SEC 1 to LH fur-nace control SEC--1 terminal.
g. Route 2--wire ALS--M connector from LH furnace toRH furnace through unused condensate drain line holewith snap bushing.
6. Install RH furnace (SECONDARY) auxiliary door switchand harness (ALS--S/ILK--1).
NOTE: RH furnace ALS--S assembly HAS door switch included.
a. Install auxiliary limit switch (ALS--S).
(1.) Drill 1/8--in. hole in blower housing 8 in. belowblower shelf as shown in Fig. 25.
(2.) Position ALS--S so terminals face front of furnace.
(3.) Secure bracket to blower housing using factory--supplied No. 6 X 3/4--in. LG screw.
b. Install auxiliary door switch (ILK--1).
(1.) Drill 7/32--in. hole in left side of RH furnaceblower shelf for mounting door switch as shown inFig. 31.
(2.) Secure ALS--S door switch (ILK--1) using factory--supplied flat screw No. 6 X 3/4--in. LG screw.
c. Connect RH furnace 2--wire ALS--S connector PL6 toLH furnace 2--wire ALS--M connector PL6 that wasrouted through furnace casings.
7. Select identical blower speed taps at blower motor connec-tions on control center in both furnaces.
UNIT DAMAGE HAZARD
Failure to follow this caution could result in unit damage.
Failure to select identical blower speed taps in both furnacescan result in overheating of furnace components and possibleloss of furnace operation and damage to the furnace.
CAUTION!
8. Dress wires to ensure they do not contact sharp edges ormoving parts, nor interfere with blower operation, removalof filters, or operation of switches.
9. Make all thermostat connections to the LH furnace only.
PROCEDURE 3 — CONNECT ELECTRICALCOMPONENTS—COOLING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in unit damage, fire,personal injury or death.
Make no connections between the R 24--vac connector in 1furnace and the R 24--vac connector in other furnace.
! WARNING
When installing twinned outdoor units with twinned gas furnaces,it is necessary to use a field--supplied 24--vac pilot--duty relay and afield--supplied 24/115--vac transformer as shown in Fig. 15, 16, or17 to prevent overloading furnace 24/115--vac transformer.
KGATW
32
A
A96128
Fig. 34 -- Rooftop Termination (Dimension “A” is Touching or2 in. (51 mm) Maximum Separation)
PROCEDURE 4 — VENTING
Refer to Installation, Start--Up, and Operating Instructions suppliedwith each furnace for venting information. Each furnace mustalways be individually vented. Do not common--vent orbreach--vent condensing furnaces. For direct--vent installations,refer to Fig. 34, 35, 36, 37, or 38 for proper termination. It isimportant that vent terminations be made as shown to avoidrecirculation of flue gases.
PROCEDURE 5 — GAS SUPPLY PIPING
NOTE: All gas connections must be made through exposed outerside of each furnace. Do not common connect any connectionother than supplyand return--air ducts.
Furnaces are recommended to be provided with a single shutoffvalve. However, individual shutoff valves may be required by localcodes or jurisdictions. Refer to Installation, Start--Up, andOperating Instructions provided with each furnace for additionalgas supply information.
PROCEDURE 6 — CONDENSATE DRAINCONNECTIONS
The condensate trap is factory installed in blower shelf and factoryconnected for UPFLOW applications. Install condensate trapextension drain such that field drain connections are on the left sidefor LH (MAIN) furnace and on right side for RH (SECONDARY)furnace. (See Fig. 28.)
The condensate trap must be relocated for downflow andhorizontal applications.
See furnace Installation, Start--Up, and Operating Instructions fordetails on attaching field drain for downflow and horizontalapplications.
PROCEDURE 7 — ELECTRICAL SUPPLYCONNECTIONS
NOTE: All electrical power connections must be made throughexposed outer side of each furnace. Do not common connect anyconnection other than supply-- and return--air ducts.
1. Each furnace shall be connected to its own 115--vac powersupply. The twinning kit installation interconnects the fur-naces, allowing them to operate as a single furnace. The L1(black) connection to each furnace must be connected to cir-cuit breakers connected to the same service panel 115--vacphase leg.On single--phase (residential) systems, each furnace circuitbreaker should be located directly across from each other in
service panel, or each furnace circuit breaker should be loc-ated on the same side of service panel, but must skip 1 spaceto be connected to the same leg of the 1--phase power sup-ply.On 3--phase (commercial) systems, each furnace circuitbreaker should be located directly across from each other inservice panel, or each furnace circuit breaker should be loc-ated on the same side of service panel, but must skip 2spaces to be connected to the same leg of the 3--phasepower supply.The proper 115--vac phasing of furnace connections permits24--vac transformer phasing as described below.
2. Phasing of the connected 24--vac transformer secondary cir-cuits can be determined with the LED status of both fur-naces. See furnace Installation, Start--Up, and Operating In-structions and status code label on blower access panel ormain furnace door. The furnaces’ transformers’ black leadsshould be connected to PR1 connectors and white leads toPR2 connectors on controls. If 1 or both LEDs are rapidlyflashing, disconnect lead at TEST/TWIN terminal of LHfurnace and observe LED at each furnace.IF:
a. Both LEDs are on continuously:System phasing is okay.
b. One or both LEDs are rapidly flashing:
(1.) Line voltage polarity is reversed.
(2.) Reverse SEC--1 and SEC--2 in furnace with rapidflashing LED.
c. One LED is off, 1 LED is on continuously:
(1.) The 24--vac circuit is inoperative on furnace withLED light off.
(2.) Check transformers, auxiliary limits, and doorswitches in both furnaces and correct problem.
3. Reconnect lead at TWIN/TEST terminal of LH furnace andobserve LED at each furnace. The LEDs will glow steadyfor proper phasing.
PROCEDURE 8 — START--UP ANDADJUSTMENT
NOTE: Refer to Installation, Start--Up, and Operating Instructionssupplied with furnace for detailed information.
1. Shut off all power and gas to both furnaces.
COMBUSTIONAIR
VENTVENT
A
A93056
Fig. 35 -- Concentric Vent and Combustion Air Roof Termina-tion (Dimension “A” is Touching or 2 in. (51 mm) Maximum
Separation)
KGATW
33
COMBUSTION AIR
VENT
A
VENT
1″ (25 mm) MAXIMUM(TYP)
A93057
Fig. 36 -- Concentric Vent and Combustion Air SideTermination (Dimension “A” is Touching or 2 in. (51 mm)
Maximum Separation)
A
COMBUSTION AIR
COMBUSTION AIR
VENT
A96129
Fig. 37 -- Sidewall Termination of 12 in. (305 mm)or Less(Dimension “A” is Touching or 2 in. (51 mm)
Maximum Separation)
2. Position blower off delay switches on controls in BOTHfurnaces to the SAME desired blower off delay in heating.See furnace Installation, Start--Up, and Operating Instruc-tion for further details.
3. Attach twinning connection wiring label above the existingfurnace wiring label on the inside of the L/H furnace bloweraccess door. Use the following labels for the following ap-plications:Single--Stage furnaces with single--stage thermostat,327893–101Single Stage furnaces with two--stage thermostat,327892–101Two--Stage furnaces with single--stage or 2–stage thermo-stat, 327891–101
4. Attach twinning reference label 327956--101 on the outsideof blower access door of RH furnace
5. Manually close the blower switch.
COMBUSTION AIRCOMBUSTION AIR
VENT
A
A96130
Fig. 38 -- Sidewall Termination of More Than 12 in.(305 mm) (Dimension “A” is Touching or 2 in. (51 mm)
Maximum Separation)
6. Turn on power and gas to furnaces.
7. Using appropriate section below, operate furnaces through 2cycles in each mode to confirm correct operation by operat-ing only the thermostat.
a. Single-- or 2--stage gas heating thermostat R--to--W/W1for low--gas heat. Single--stage thermostat with adaptiveheating mode causes furnace to operate in low--gas--heatmode for up to 16 minutes, and then furnace automatic-ally switches to high--gas heat. First stage of a 2--stagethermostat without adaptive heating mode causes fur-nace to operate in low--gas--heat mode indefinitely.
b. First and second--stage of 2--stage heating thermostatR--to--W/W1--and--W2 for high--gas--heat.
c. Thermostat R--to--G for continuous fan or 2--stage cool-ing low--cool blower.
d. Cooling thermostat R--to--G--and--Y/Y2 for single--speedcooling blower or for 2--stage cooling high--cool blower.
8. Reinstall control doors on both furnaces.
9. Instruct user in operation of furnaces and thermostat.
PROCEDURE 9 — SEQUENCE OFOPERATION
See Fig. 15, 16, or 17, and 39 or 40 for condensing furnacetwinning connection and schematic wiring diagrams whilereviewing sequence of operation.
Twinning operation is controlled by LH or MAIN furnace. TheTEST/TWIN connection wire ensures the 2 furnaces coordinatetheir blower operation. When either furnace requires bloweroperation, both furnace blowers operate at same speed. Bothfurnaces operate simultaneously in the same mode: heat, cool, orcontinuous fan. Exceptions can occur if a safety switch on eitherfurnace is opened by a problem (such as pressure switch, flameroll--out switch, main limit switch, twinning kit auxiliary limitswitch, or flame--proving sensor). In such a case, the other furnacecontinues to operate unless open switch is the flame roll--out, mainlimit, or twinning kit auxiliary limit switch, in which case bothfurnaces respond.
Before performing component test, disconnect TKR yellow wirelabeled TEST from LH furnace control center TEST/TWINterminal. After removing yellow wire, component test can beinitiated on each furnace individually as stated in Installation,Start--Up, and Operating Instructions.
KGATW
34
A. Fixed Capacity FurnacesSINGLE--STAGE HEAT, SINGLE STAGE FURNACESWITH SINGLE--STAGE GAS--HEAT THERMOSTATOperation in all modes (sequence of operation) is the same fortwinned furnaces as for an individual furnace. See furnaceInstallation, Start--Up, and Operating Instructions for moreinformation on the sequence of operation.
TWO--STAGE HEAT, SINGLE STAGE FURNACES WITH2--STAGE GAS--HEAT THERMOSTAT
1. The two--stage thermostat determines if furnaces are operat-ing in first--stage heat (LH furnace operates in heat whileRH furnace blower operates but RH furnace is not heating)or if furnaces are operating in second--stage heat (both fur-naces operate in heat), depending on how many thermostatstages are calling for heat. If two--stage cooling is used, Y1from the thermostat will initiate both furnace blowers to thecooling speed and the first A/C unit. Y2 from the thermostatwill go directly to the outdoor unit and initiate the secondA/C unit.
2. Operation in all modes (sequence of operation) is the samefor twinned furnaces as for an individual furnace. See fur-nace Installation, Start--Up, and Operating Instructions formore information on sequence of operation.
TWO--STAGE HEAT, TWO STAGE FURNACES WITHSINGLE--STAGE GAS--HEAT THERMOSTATNOTE: See Section 2, Procedure 2 -- Electrical Connections, Step3 for control board wiring and LHT switch setup.
1. LH furnace control determines whether furnaces are bothoperating in low--gas heat or high--gas heat, depending onthe control’s adaptive gas heating mode when the R--to--W/W1 circuit is closed in LH furnace.
2. Operation in all modes (sequence of operation) is the samefor twinned furnaces as for an individual furnace. See fur-nace Installation, Start--Up, and Operating Instructions formore information on sequence of operation.
TWO--STAGE HEAT, TWO STAGE FURNACES WITH2--STAGE GAS--HEAT THERMOSTATNOTE: See Section 2, Procedure 2 -- Electrical Connections, Step3 for control board wiring and LHT switch setup.
1. The 2--stage thermostat (NOT furnace control’s adaptive gasheating mode) determines whether furnaces are both operat-ing in low--gas heat or high--gas heat, depending on whether1 or both thermostat stages (W/W1 or W/W1--and--W2) arecalling for heat.
2. Operation in all modes (sequence of operation) is the samefor twinned furnaces as for an individual furnace. See fur-nace Installation, Start--Up, and Operating Instructions formore information on sequence of operation.
KGATW
35
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ENT-
SPLI
T-CA
PACI
TOR
CAP
1, 2
CAPA
CITO
RCP
UM
ICRO
PRO
CESS
OR
AND
CIR
CUIT
RYEA
C-1
ELEC
TRO
NIC
AIR
CLEA
NER
CON
NECT
ION
(115
VAC
1.0
AMP
MAX
.)EA
C-2
ELEC
TRO
NIC
AIR
CLEA
NER
CON
NECT
ION
(CO
MM
ON)
FRS
FLAM
E RO
LLO
UT S
W. -
MAN
UAL
RESE
T, SP
ST-(N
.C.)
FSE
FLAM
E-PR
OVIN
G EL
ECTR
OD
EFU
1FU
SE, 3
AM
P, AU
TOM
OTI
VE B
LAD
E TY
PE, F
ACTO
RY IN
STAL
LED
FU 2
FUSE
OR
CIRC
UIT
BRE
AKER
CUR
RENT
INTE
RRUP
T D
EVIC
E(F
IELD
INST
ALLE
D &
SU
PPLI
ED)
GND
EQUI
PMEN
T GR
OUN
DGV
GAS
VALV
E-RE
DUN
DAN
TGV
R 1,
2GA
S VAL
VE R
ELAY
, DPS
T-(N
.O.)
HSI
HOT
SURF
ACE
IGN
ITER
(115
VAC)
HSIR
HOT
SURF
ACE
IGN
ITER
REL
AY, S
PST-
(N.O
.)HU
M24
VAC
HUM
IDIF
IER
CONN
ECTI
ON
(0.5
AM
P. M
AX.)
IDM
IND
UCE
D D
RAFT
MOT
OR,
PSC
IDR
IND
UCE
D D
RAFT
MOT
OR
RELA
Y, SP
ST-(N
.O.)
ILK
BLO
WER
ACC
ESS
PANE
L IN
TERL
OCK
SW
ITCH
, SPS
T-(N
.O.)
J1BL
OW
ER -
OFF
DEL
AY JU
MPE
R SE
LECT
OR
JBJU
NCTI
ON
BO
XLE
DLI
GHT
-EM
ITTI
NG D
IOD
E FO
R ST
ATUS
CO
DES
- AM
BER
LGPS
LOW
GAS
PRE
SSUR
E SW
ITCH
, SPS
T-(N
.O.)
LSLI
MIT
SW
ITCH
, AUT
O-R
ESET
, SPS
T (N
.C.)
OL
AUTO
-RES
ET IN
TERN
AL M
OTO
R OV
ERLO
ADTE
MPE
RATU
RE S
WIT
CH (N
.C.)
PCB
PRIN
TED
CIR
CUIT
BO
ARD
CO
NTRO
LPL
111
-CIR
CUIT
PCB
CO
NNEC
TOR
PL2
2-CI
RCUI
T CO
NNEC
TOR
PL3
2-CI
RCUI
T HS
I, C
ONN
ECTO
RPL
43-
CIRC
UIT
IDM
EXT
ENSI
ON
CO
NNEC
TOR
PRS
PRES
SURE
SW
ITCH
, SPS
T-(N
.O.)
TEST
/TW
INCO
MPO
NENT
TES
T &
TWIN
TER
MIN
ALTR
ANTR
ANSF
ORM
ER-1
15VA
C/24
VAC
JUNC
TIO
N
UNM
ARKE
D T
ERM
INAL
PCB
CON
TRO
L TER
MIN
AL
FACT
ORY
WIR
ING
(115
VAC)
FACT
ORY
WIR
ING
(24V
AC)
FIEL
D W
IRIN
G (1
15VA
C)
FIEL
D W
IRIN
G (2
4VAC
)
COND
UCTO
R O
N CO
NTRO
L PC
B
FIEL
D W
IRIN
G SC
REW
TER
MIN
AL
FIEL
D E
ARTH
GRO
UND
EQUI
PMEN
T GR
OUN
D
FIEL
D S
PLIC
E
PLUG
REC
EPTA
CLE
1.If
any
of th
e or
igin
al e
quip
men
t wire
is re
plac
ed u
se w
ire ra
ted
for 1
05°C
.2.
Use
onl
y co
pper
wire
bet
wee
n th
e di
scon
nect
sw
itch
and
the
furn
ace
junc
tion
box
(JB)
.3.
This
wire
mus
t be
conn
ecte
d to
furn
ace
shee
t met
al fo
r con
trol t
o pr
ove
flam
e.4.
Sym
bols
are
ele
ctric
al re
pres
enta
tion
only.
5.So
lid li
nes
insi
de P
CB
are
prin
ted
circ
uit b
oard
con
duct
ors
and
are
not i
nclu
ded
in le
gend
.6.
Rep
lace
onl
y w
ith a
3 a
mp
fuse
.7.
Indu
cer (
IDM
) and
blo
wer
(BLW
M) m
otor
s co
ntai
n in
tern
al a
uto-
rese
t the
rmal
ove
rload
sw
itche
s (O
L).
8.N
eutra
l con
nect
ions
are
inte
rcha
ngea
ble
with
in th
e N
EUTR
AL c
onne
ctor
blo
ck.
9.Bl
ower
mot
or s
peed
sel
ectio
ns a
re fo
r ave
rage
con
ditio
ns, s
ee in
stal
latio
n in
stru
ctio
ns fo
r det
ails
on
optim
um s
peed
sel
ectio
n.10
.YE
LLO
W le
ad n
ot o
n al
l mot
ors.
11.
Fact
ory
conn
ecte
d w
hen
LGPS
is n
ot u
sed.
12.
Igni
tion-
lock
out w
ill oc
cur a
fter f
our c
onse
cutiv
e un
succ
essf
ul tr
ials
-for-i
gniti
on. C
ontro
l will
auto
-rese
t afte
r thr
ee h
ours
.13
.Bl
ower
-on
dela
y: g
as h
eatin
g 60
sec
onds
, coo
ling
or h
eat p
ump
2 se
cond
s.14
.Bl
ower
-off
dela
y: g
as h
eatin
g se
lect
ions
are
90,
120
, 150
or 1
80 s
econ
ds, c
oolin
g or
hea
t pum
p90
sec
onds
or 5
sec
onds
whe
n de
hum
idify
cal
l is
activ
e.
NO
TE #
10
PRINTED CIRCIUT BOARD
PRINTED CIRCIUT BOARD
NO
TE #
5
A02157
Fig. 39 -- Fixed--Capacity Condensing Furnace Wiring Diagram
KGATW
36
GV
HIM
GR
N/Y
EL
CN
OTE
#3
BRN
BLU
BRN
GR
N/Y
EL
RED
RED
FRS
LS
NO
TE #
11
OR
NYE
L
HSI
L1N
OTE
#2
GN
D
NEU
TRAL
FU2
FUSE
OR
CIR
CUI
TBR
EAKE
R &
DIS
CO
NN
ECT
SWITC
H (W
HEN
REQ
'D)
BLK
ILK
PL5
JB
1 2
SEC-1
LEDSEC-2
FUSE 3-AMPPL
T
AC
RD
J
0.5 AMP@ 24 VAC
HUM
TEST/TWIN
ON
OFF
32
1
DLYOFFLHT
W/W
1D
HU
MG
24Vom
CW
2Y
/Y2
RY
1
TRAN
L1
PR-1
EAC-1
OL
SPARE - 1
BLWR BHT/CLR BHI/LOR
COOL LO-HEAT
HI-HEAT
STA
RT
GR
N/Y
EL
BLW
M
NEUTRAL - L2 EAC-2R
ED
BLU
OR
NYE
LBL
K
LOM
ED L
OM
EDHI
MED
HI
RED
BLU
WH
TW
HT
BRN
BRN
BLK
WH
T
BLK
WH
T
IHI/L
OR
HSI
R
IDR
LO HI HSI
GR
Y
CO
NN
ECTI
ON
DIA
GR
AM
BLK
1H
SI2
IDM
12 3H
I
CO
M
LO
S
CH
EMAT
IC D
IAG
RAM
(NAT
UR
AL G
AS &
PR
OPA
NE)
IDR
T
O 1
15VA
C F
IELD
-DIS
CO
NN
ECT
SWIT
CH
ILK
EQU
IPM
ENT
GR
OU
ND
12 3H
SIR
IHI/L
OR
PL2L2
L2
CAP
-1
OL
STAR
T
BLW
M
CO
M
LOM
ED L
OM
ED HI
ME
D H
I
LO H
EAT
SPA
RE-
2C
OO
LIN
G
SPAR
E-1
BHI/L
OR
BHT/
CLR
BLW
R
EAC
-2EA
C-1
TRAN
L2
L2
115V
AC
24VA
CSE
C 2
SEC
1
PR
1
FU1
NO
TE #
6
PL1-
8G
VR
-2H
UM R
AC
RPL
1-12
HP
SR
GV
LPS
NO
TE #
11
LGP
S(W
HEN
USE
D)
HPS HI
PL1-
2
PL1-
4
PL1-
3
PL1-
10
PL1-
5
W/W
1
CP
U
GVR
-1
TEST
/TW
IN
DH
UM
W2
Y/Y2
G Y1 CO
M 2
4VN
OTE
#3 CM
PL1-
1
LPS
(WH
EN
US
ED
)LG
PS
WH
T
FSE
PL1-
9
PL1-
11
PL1-
7
LEG
EN
D
AC
RA
IR C
ON
DITI
ON
ING
REL
AY, S
PST
(N.O
.)A
CRD
JA
IR C
ON
DITI
ON
ING
REL
AY D
ISA
BLE
JUM
PER
BHI/L
OR
BLO
WER
MO
TOR
SPEE
D C
HA
NG
E RE
LAY,
SPD
TBH
T/C
LRBL
OW
ER M
OTO
R SP
EED
CH
AN
GE
RELA
Y, S
PDT
BLW
RBL
OW
ER M
OTO
R RE
LAY,
SPS
T-(N
.O.)
BLW
MBL
OW
ER M
OTO
R, P
ERM
AN
ENT-
SPLI
T-C
APA
CITO
RC
AP
1, 2
CA
PAC
ITO
RC
PUM
ICRO
PRO
CES
SOR
AN
D C
IRC
UITR
YD
HUM
DH
UM C
ON
NEC
TION
EA
C-1
ELEC
TRO
NIC
AIR
CLE
AN
ER C
ON
NEC
TION
(115
VA
C 1
.0 A
MP
MA
X.)
EAC
-2EL
ECTR
ON
IC A
IR C
LEA
NER
CO
NN
ECTIO
N (C
OM
MO
N)
FRS
FLA
ME
ROLL
OU
T SW
. -M
AN
UAL
RESE
T, SP
ST-(
N.C
.)FS
EFL
AM
E-PR
OV
ING
ELE
CTR
OD
EFU
1FU
SE, 3
AM
P, A
UTO
MO
TIVE
BLA
DE
TYPE
, FA
CTO
RY IN
STA
LLED
FU2
FU
SE O
R C
IRC
UIT
BREA
KER
CU
RREN
T IN
TERR
UPT
DEV
ICE
(FIE
LD S
UPPL
IED
AN
D IN
STA
LLED
)G
ND
EQU
IPM
ENT
GRO
UND
GV
GA
S VA
LVE-
RED
UND
AN
T G
VR
1, 2
GA
S VA
LVE
RELA
Y, D
PST-
(N.O
.)H
PSH
IGH
-HEA
T PR
ESSU
RE S
WITC
H, S
PST
(N.O
.)H
PSR
HIG
H-H
EAT
PRES
SURE
SW
ITCH
REL
AY, S
PST
(N.C
.)H
SIH
OT
SURF
AC
E IG
NIT
ER (1
15VA
C)
HSI
RH
OT
SURF
AC
E IG
NIT
ER R
ELAY
, SPS
T (N
.O.)
HUM
24VA
C H
UM
IDIF
IER
CO
NN
ECTIO
N (0
.5 A
MP.
MA
X.)
IDM
IND
UC
ED D
RAFT
MO
TOR,
2-S
PEED
, SH
AD
ED P
OLE
IDR
IND
UC
ED D
RAFT
MO
TOR
RELA
Y, S
PST-
(N.O
.)IH
I/LO
RIN
DU
CER
MO
TOR
SPEE
D C
HA
NG
E RE
LAY,
SPD
TIL
KBL
OW
ER A
CC
ESS
PAN
EL IN
TERL
OC
K SW
ITCH
, SPS
T-(N
.O.)
JBJU
NC
TION
BO
XLE
DLI
GH
T-EM
ITTIN
G D
IOD
E FO
R ST
ATU
S C
OD
ES -
AM
BER
LGPS
LOW
GA
S PR
ESSU
RE S
WIT
CH
, SPS
T-(N
.O.)
LPS
LOW
-HEA
T PR
ESSU
RE S
WITC
H, S
PST
(N.O
.)LS
LI
MIT
SW
ITC
H, A
UTO
-RES
ET, S
PST
(N.C
.)O
LA
UTO
-RES
ET IN
TERN
AL
MO
TOR
OV
ERLO
AD
TEM
PERA
TURE
SW
ITCH
(N.C
.)PC
BPR
INTE
D C
IRC
UIT
BOA
RD C
ON
TRO
L
PL1
12-C
IRC
UIT
PCB
CO
NN
ECTO
RPL
23-
CIR
CU
IT PC
B H
SI &
IDM
CO
NN
ECTO
RPL
36-
CIR
CU
IT IC
M M
OTO
R C
ON
NEC
TOR
(NO
T SH
OW
N)
PL4
4-C
IRC
UIT
IDM
CO
NN
ECTO
R PL
52-
CIR
CU
IT H
SI C
ON
NEC
TOR
PLT
3-C
IRC
UIT
FAC
TORY
TES
T C
ON
NEC
TOR
TRA
NTR
AN
SFO
RMER
, 115
VAC
/24V
AC
TEST
/TW
INC
OM
PON
ENT
TEST
& T
WIN
NIN
G T
ERM
INA
L
JUN
CTIO
N
TERM
INA
L
CO
NTR
OL
PCB
TERM
INA
L
FAC
TORY
PO
WER
WIR
ING
(115
VAC
)
FAC
TORY
CO
NTR
OL
WIR
ING
(24V
AC
)
FIEL
D C
ON
TRO
L W
IRIN
G (1
15VA
C)
FIEL
D C
ON
TRO
L W
IRIN
G (2
4VA
C)
CO
ND
UC
TOR
ON
CO
NTR
OL
PCB
FIEL
D W
IRIN
G S
CRE
W T
ERM
INA
L
FIEL
D E
ART
H G
ROU
ND
EQUI
PMEN
T G
ROU
ND
FIEL
D S
PLIC
E
PLU
G R
ECEP
TAC
LE
PCB
PL1-
6
L1
NO
TE #
10
L2
PL4
PL5
WH
T
WH
T
RED BLK
PL2
IDM
NOTE #8
1 AMP @ 115 VAC
STA
TUS
CO
DE
FU1NOTE #6
PL1
1
SELE
CT
CH
ART
SWLO
-HT
ON
LYB
LOW
ERO
FF-D
ELA
Y
ON
OFF
1
ON
LYH
EAT
LOHEA
TN
OR
M2
390 SE
C.
ON
OFF
12
312
0SE
C.
ON
OFF
23
150
SEC
.
ON
OFF
23
180
SEC
.
HP
S
FAC
TOR
Y S
ETTI
NG
S
BLW
HI H
EAT
NO
TE #
5
*
*
*
SPARE-2
FSE
RED
ACRDJ
3267
97-1
01 R
EV. A
1.If
any
of th
e or
igin
al e
quip
men
t wire
is re
plac
ed u
se w
ire ra
ted
for 1
05∞C
.2.
Use
onl
y co
pper
wire
bet
wee
n th
e di
scon
nect
sw
itch
and
the
furn
ace
junc
tion
box
(JB
).3.
This
wire
mus
t be
conn
ecte
d to
furn
ace
shee
t met
al fo
r con
trol
to p
rove
flam
e.4.
Sym
bols
are
ele
ctric
al re
pres
enta
tion
only
.5.
Solid
line
s in
side
PC
B a
re p
rinte
d ci
rcui
t boa
rd c
ondu
ctor
s an
d ar
e no
t inc
lude
d in
the
lege
nd.
6.R
epla
ce o
nly
with
a 3
am
p fu
se.
7.B
low
er m
otor
(BLW
M) a
nd in
duce
r mot
or (I
DM
) con
tain
inte
rnal
aut
o-re
set t
herm
al o
verlo
ad s
witc
hes
(OL)
.8.
Neu
tral
con
nect
ions
are
inte
rcha
ngea
ble
with
in th
e N
EUTR
AL
conn
ecto
r blo
ck.
9.B
low
er m
otor
spe
ed s
elec
tions
are
for a
vera
ge c
ondi
tions
, see
inst
alla
tion
inst
ruct
ions
for o
ptim
um s
elec
tion.
10.M
ED n
ot a
vaila
ble
on s
ome
mod
els.
11.F
acto
ry c
onne
cted
whe
n LG
PS is
not
use
d.12
.Ign
ition
lock
out w
ill o
ccur
afte
r fou
r con
secu
tive
unsu
cces
sful
tria
ls-fo
r-ig
nitio
n. C
ontr
ol w
ill a
uto-
rese
t afte
rth
ree
hour
s.13
.Blo
wer
-on
dela
y: g
as h
igh-
heat
60
seco
nds,
gas
low
-hea
t 45
seco
nds,
coo
ling
or h
eat p
ump
2 se
cond
s.14
.Blo
wer
off-
dela
y: g
as h
eatin
g se
lect
ions
are
90,
120
, 150
, 180
sec
onds
, coo
ling
or h
eat p
ump
90 s
econ
ds o
r 5
seco
nds
whe
n de
hum
idify
cal
l is
activ
e.
NO
TE
S:
PRINTED CIRCIUT BOARD
PRINTED CIRCIUT BOARD
FRS
LS
WHT
WHT
PL3
IDM
12
3
BLK
4
GRN/YEL
CAP
-2B
RN
BRN
GR
N
RED
WHT
OL
/YEL
CA
P-1
NO
TE #
2
OL
4
CAP-2
NO
TE #
9
A02255
Fig. 40 -- Two--Stage Condensing Furnace Wiring Diagram
KGATW
37
Table 5 – Single--Stage Heating with Single--Stage Thermostat Using Two Single--Stage FurnacesTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatW W Starts L/H and R/H furnaces for heating
Table 6 – Single--Stage Cooling with Single--Stage Thermostat Using Two Single--Stage A/C UnitsTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatY Y/Y2 (Y on standard control board) Energizes accessory cooling relay(s) to start L/H and R/H A/C for
coolingG G Starts both indoor fans on cooling speed (With Y/Y2 energized)
Dehum* Dehum* Reduces airflow in cooling mode from cooling speed to heatingspeed when Dehum input is removed
*Dehum is not available on all thermostats or control boards
Table 7 – Two--Stage Heating with Two--Stage Thermostat Using Two Single--Stage FurnacesTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatW1 W Starts L/H furnace for first stage heatingW2 None Thermostat W2 wired directly to R/H accessory relay to start
R/H Furnace for second stage heating
Table 8 – Two--Stage Cooling with Two--Stage Thermostat Using Two Single--Stage A/C UnitsTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatY1 Y/Y2 (Y on standard control board) Energizes accessory cooling relay to start L/H and A/C for first
stage cooling and cooling speed blowerY2 None Thermostat Y2 wired directly to R/H accessory relay to start R/H
A/CG G Starts both indoor fans on cooling speed (With Y/Y2 energized)
Dehum* Dehum* Reduces airflow in cooling mode from cooling speed to heatingspeed when Dehum input is removed
*Dehum is not available on all thermostats or control boards
Table 9 – Continuous Fan OperationTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatG G Starts both fans in heating speed*
*Staged continuous Fan operation is not available
Table 10 – Two--Stage Heating with Single--Stage Thermostat Using 2 Two--Stage FurnacesTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatW W/W1 Starts L/H and R/H furnaces in low heat or high heat, as deter--
mined by L/H furnace control board**LHT switches must be in correct configuration
Table 11 – Two--Stage Heating with Two--Stage Thermostat Using 2 Two--Stage FurnacesTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatW1 W/W1 Starts both furnaces in low heat for first stage heating*W2 W2 Starts both furnaces in high heat for second stage heating*
*LHT switches must be in correct configuration
Table 12 – Single--Stage Cooling with Single--Stage Thermostat Using 2 Single--Stage A/C UnitsTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatY Y/Y2 Energizes accessory cooling relay to start both A/C units for
coolingG G Starts both indoor fans on cooling speed (With Y/Y2 energized)
Dehum* Dehum** Reduces airflow in cooling mode from cooling speed to heatingspeed when Dehum input is removed
*Do not remove ACRDJ from furnace control boards** Dehum is not available on all thermostats or control boards
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Table 13 – Two--Stage Cooling with Two--Stage Thermostat Using 2 Single--Stage A/C UnitsTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatY1 Y/Y2 Energizes accessory cooling relay to start L/H A/C for first stage
coolingY2 None Thermostat Y2 wired directly to R/H accessory relay to start R/H
A/CG G Starts both indoor fans on heating speed until Y/Y2 is energized
Dehum* Dehum** Reduces airflow in cooling mode from cooling speed to heatingspeed when Dehum input is removed
*Do not remove ACRDJ from furnace control boards** Dehum is not available on all thermostats or control boards
Table 14 – Continuous Fan OperationTHERMOSTAT CONNECTIONS CONTROL BOARD CONNECTION ACTION
R R Power from control board to thermostatG G Starts both fans in heating speed*
*Staged Continuous Fan operation is not available
Copyright 2010 CAC / BDP D 7310 W. Morris St. D Indianapolis, IN 46231 Printed in U.S.A. Edition Date: 10/10
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Catalog No: AG---GATW---17
Replaces: AG---GATW---16
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