service installation specifications...3.homeowner / electrician to install "9s" meterbase...

SERVICE

INSTALLATION

SPECIFICATIONS

EFFECTIVE DATE: JANUARY 2020

P O Box 959 1009 East Main Street Brownsville, TN 38012

www.stemc.com Brownsville Jackson Covington Henderson Atoka

November 30, 2015

Dear STEMC Member and Contractors,

Over the years, STEMC has made many changes to its member requirements for new services and specifications associated

with those requirements. As a matter of consistency for members and contractors, STEMC has compiled and revised

several drawings used to aid members and their contractors installing facilities for new services.

ANY SPECIFICATION DRAWINGS OR DATED PRIOR TO SEPTEMBER 2015 WILL NOT BE HONORED.

In conjunction with this, STEMC has updated several OPERATIONAL PROCEDURES in an effort to bring STEMC more in-line

with other utility best practices. These revisions mutually benefit STEMC and the member.

OPERATING PROCEDURES WILL BECOME EFFECTIVE JANUARY 1, 2016.

If you have any questions regarding the changes, please contact myself or your local STEMC Engineering Coordinator.

Kind regards,

William V. Gordon, P.E. Vice President of Engineering SOUTHWEST TN EMC P.O. Box 959 | 1009 East Main Street Brownsville, TN 38012 (office) 731.585.0538 (fax) 731.772.103

Southwest TN EMC

Operating Procedure

Underground Residential Service

To: Engineering Coordinators

From: William V. Gordon

Date: November 30, 2015

Re: Underground Residential Service

Effective January 1, 2016, STEMC members (or their electrical contractor) shall install conduit to the

following specifications for underground secondary service. Remember to dial 811 three-days prior to any

digging.

Conduit shall be 3-inch PVC Schedule 80 above ground and PVC or HDPE Schedule 40 or 80

below ground. Conduit shall be installed at a minimum depth of 30-inches.

90s at STEMC point of feed and meterbase may be short sweeping (no plumbing fittings), but all

others shall be long sweeping. Two (2) 45s may be used at meterbase given a minimum 2-foot

section of straight conduit is installed between 45s. Conduit shall stop a minimum of 3-feet from

STEMCs point of feed (leave 90 and additional conduit on site) or contact STEMC to open point of

feed. Conduit shall have pull string installed throughout the entire length.

Contact your nearest STEMC office to schedule a ditch/conduit inspection. All conduits and

90s/45s shall be visible.

Point of feed may be considered a padmounted transformer, handhole, or pole.

If point of feed is pole, 1-stick of Schedule 80 PVC conduit shall be turned up at the pole

Southwest TN EMC

Operating Procedure

Underground Primary Extension




Re: Underground Primary Extension

Effective January 1, 2016, STEMC members (or their electrical contractor) shall install 2-inch conduit for

the installation of primary cables. Conduit shall be installed per specification drawing TRD. Depending on

length of installation, STEMC may require placement of primary junction box to reduce pulling length. Direct

burial method may still be utilized at the discretion of STEMC Engineering.

Southwest TN EMC

Operating Procedure

Underground Secondaries for General Power Accounts




Re: Underground Secondaries for General Power Accounts

Effective January 1, 2016, STEMC members (or their electrical contractor) shall install their own conduit

and secondary wiring to the point of feed (padmounted transformer, handhole, or pole) for general power

service. Conduit and secondary wiring shall be installed per specification drawing TDSEC. This includes

single and three-phase applications. For installations where point of feed is a padmounted transformer,

members (or their electrical contractor) shall be responsible for providing terminating lugs.

Single-phase general power accounts located on residential properties are exempt from providing

secondary wire to the point of feed, so long as they are not being used as a place of business. Example:

shops, gates, barns, pool houses are exempt.

CONTENTS

DRAWING TITLE (DESCRIPTION) PAGE

MBR SVC POLE ................................................................................................................................. 1

OH TEMP.......................................................................................................................................... 2

UG TEMP .......................................................................................................................................... 3

CT 1P ................................................................................................................................................ 4

CT 3P ................................................................................................................................................ 5

TD SEC .............................................................................................................................................. 6

TRD .................................................................................................................................................. 7

PM 1P SD ......................................................................................................................................... 8

PM 1P .............................................................................................................................................. 9

PM 3P 75-500 ................................................................................................................................ 10

PM 750-2500 ................................................................................................................................. 11

PBD ................................................................................................................................................ 12

PMC1 ............................................................................................................................................. 13

PMC2 ............................................................................................................................................. 14

TUCS .............................................................................................................................................. 15

URD STAKING ................................................................................................................................. 16

CONTACTS

ATOKA ENGINEERING ................................................................................................ (901) 622-0603

BROWNSVILLE ENGINEERING .................................................................................... (731) 585-0103

COVINGTON ENGINEERING ....................................................................................... (901) 622-0305

HENDERSON ENGINEERING ....................................................................................... (731) 520-0407

JACKSON ENGINEERING ............................................................................................ (731) 554-1206

5'-6"

SERVICE ENTRANCECONDUCTORS SHALL EXTEND 18"

FROM WEATHERHEAD WITHNEUTRAL MARKED IN WHITE.

5/8" x 8' GROUND RODBONDED TO GROUND WIRE

WITH CLAMP INSTALLEDBELOW GRADE.

EXIT CONDUIT LAYOUT WILLVARY BASED ON MEMBERNEEDS.

3000-PSI CONCRETE WITH MINIMUM48 HOUR CURE TIME.

16'

4'

DISCONNECT

METERBASE

CONDUIT STRAP

Southwest Tennessee ElectricMembership Corporation

A Touchstone Energy® Cooperative

MEMBER OWNED SERVICE POLE SPEC

JANUARY 2020 MBR SVC POLE

NOTES:1. Obtain approval for pole location and height from STEMC engineering prior to commencing work.

2. STEMC no longer issues permits. Contact local office for list of locations to obtain permits.

3. 20' pole with 6" minimum diameter shall be buried 4' below ground level. Any pole height other than 20'

must be approved by STEMC engineering.

4. Concrete shall be placed around pole, visible at ground level, and cured 48 hours.

5. Guy and anchor shall be set if service length is greater than 100', or as required by STEMC engineering.

6. Clearance to drip loop shall be a minimum of 12' above ground level. If service crosses driveways or public

streets minimum clearance could be extended up to 18'.

7. Service wire crossing a roof shall have minimum clearance of 8' where crossing.

8. STEMC provided eyebolt shall be installed 6" from top of pole.

ALL SERVICES SHALL MEET

NATIONAL ELECTRICAL CODE

STANDARDS.

1

36" RECOMMENDED MINIMUM

48" RECOMMENDED MINIMUM

GRADE

CONCRETE

GROUND ROD

60 AMP

MINIMUM

DISCONNECT

METERBASE

CONDUIT STRAP

SERVICE ENTRANCECONDUCTORS SHALL EXTEND 18"

FROM WEATHERHEAD WITHNEUTRAL MARKED IN WHITE.



TEMPORARY OVERHEAD SERVICE DETAIL

JANUARY 2020 OH TEMP

NOTES:1. Use 3 - #6 service entrance conductors. must extend at least 18 inches from weatherhead.2. Minimum 1" conduit and weatherhead must extend to top of pole. Raceway may be rigid, EMT, IMC or

Schedule 40 PVC. EMT must have water tight fittings.3. A ground wire of #6 copper or larger shall be run, unspliced, from the meter socket to a driven ground

rod.4. A 6" x 6" square or 6" diameter (at top) round pole embed a minimum of 4 ft. below ground,

recommended with concrete placed around base. Minimum of 16' pole required.5. Point of attachement (eyebolt) must be of sufficient height ot provide proper clearance by NESC.6. Point of attachment must be mounted at or below weatherhead.7. Meter socket to be mounted not less than 5' and not more than 6' from ground.8. All 120/240 volt receptacles must be GFCI protected and have "in use" covers.9. An 8' x 5/8" ground rod bonded to ground wire with clamp sutiable for direct burial will be installed

below grade.



STANDARDS.

2

5'

8'

3'

6'

1 2 3 4

25

4' MAXIMUM

2'

DISCONNECT

METERBASE



TEMP UNDERGROUND SERVICE DETAIL

JANUARY 2020 UG TEMP

NOTES:1. 8' Pole or timber with 4" minmum diameter shall be buried 3' below ground level.2. Backfill and tamp with clean native earth. Tamping shall provide sufficient support to set meter.

Unsecured temporaries will be truned down upon inspection.3. Service whip shall be a minimum of 6' in length when extended from pole. Whip shall be comprised of

flexible, non-metallic conduit, containing appropriately sized wire for disconnect.4. In addition to whip, conductor pigtail must extend 2 feet from end of flexible conduit.5. Coordinate transformer entry with local STEMC engineering.6. Temporary service pole must be set within 4 feet of existing STEMC padmount transformer.



STANDARDS.

3

CT "DOT TO THE POT/TRANSFORMER"

LINE SIDE

LOAD SIDE

36" MIN

36" MIN

1" NIPPLE

SERVICE ENTRANCE LAYOUT MAYVARY AS NEEDED.

CT

STEMC WILL PROVIDE SERVICE CONDUCTOR FORRESIDENTIAL MEMBERS. MEMBER TO PROVIDE CONDUIT.



SINGLE PHASE 600 AMP INSTRUMENT RATED SERVICE

TYPICAL DETAIL

JANUARY 2020 CT 1P

NOTES:1. STEMC to provide "4s" meterbase and two "CTs."

2. Homeowner / Electrician to provide 36"x36"x12" minimum weatherproof enclosure with backplate and

locking provisions.

3. Homeowner / Electrician to install "4s" meterbase and 36" enclosure connected with 1 inch nipple.

4. Homeowner / Electrician to install CTs on backplate of 36" enclosure.

5. Polarity dot on CTs must be on line side of cable. See Figure 1.

6. Wiring from CTs to meter will be completed by STEMC.

7. OH or UG to be determined by load and transformer sizing per STEMC engineering.

8. Services larger than 600 amps will be required to be underground. These installations may need parallel

conduits and may need CTs to be placed at padmount transformer.

ALL SERVICES SHALL

MEET NATIONAL

ELECTRICAL CODE

STANDARDS.

FIGURE 1

4

PT

CT "DOT TO THE POT/TRANSFORMER"

LINE SIDE

LOAD SIDE

36" MIN

36" MIN

1" NIPPLE

SERVICE ENTRANCE LAYOUT MAYVARY AS NEEDED.

CT

PT



THREE PHASE 600 AMP INSTRUMENT RATED SERVICE

TYPICAL DETAIL

JANUARY 2020 CT 3P

ALL SERVICES SHALL

MEET NATIONAL

ELECTRICAL CODE

STANDARDS.

NOTES:1. STEMC to provide "9s" Meterbase, 3 "CTs," and 3 "PTs" if necessary. (PTs only on 277/480 installations).

2. Homeowner / Electrician to provide 36"x36"x12" minimum weatherproof enclosure with backplate and

locking provisions.

3. Homeowner / Electrician to install "9s" meterbase and 36" enclosure connected with 1 inch nipple.

4. Homeowner / Electrician to install CTs on backplate of 36" enclosure.

5. Polarity dot on CTs must be on line side of cable. See Figure 1.

6. Wiring from CTs and PTs to meter will be completed by STEMC.

7. OH or UG to be determined by load and transformer sizing per STEMC engineering.

8. Services larger than 600 amps will be required to be underground. These Installations may need parallel

conduits and may need CT's to be placed at padmount.

FIGURE 1

5

GRADE

3" CONDUITQTY DETERMINED

BY MEMBERS NEEDS.

WARNINGTAPE

CLEAN FILL

FINAL

STEMC PRIMARY

SECTION A-A'

A

A'

COORDINATE FINAL INSTALL WITHSTEMC. OBSERVE APPLICABLE OSHAMINIMUM APPROACH STANDARDSAT ALL TIMES.

12"

18"

CONTRACTOR TO LEAVE6 FT. OF SECONDARY

(MINIMUM) FOR STEMCCONNECTION TO THE

TRANSFORMER

TELEPHONE ORCABLE TV

CONDUIT TO CONFORM TOLATEST NESC AND NEC

REQUIREMENTS.

STANDOFF BRACKETS, MACHINE BOLTS,WASHERS, LOCK NUTS , AND LAG SCREWS

PROVIDED BY STEMC (NOT PROVIDED IFSINGLE CONDUIT IS INSTALLED).

36" APPROX.

40" MINIMUM



TRENCH AND RISER DETAIL FOR

MEMBER OWNED

UNDERGROUND SECONDARY

JANUARY 2020 TD SEC

NOTES:1. All conduit above final grade to be schedule 80 pvc or rigid steel.

2. All conduit below final grade to be pvc or hdpe (schedule 40 or 80).

3. Backfill with clean native earth and machine tamp.

4. The State of Tennessee requires a rough-in inspection on trench for member owned secondaries. This

applies to commercial general power accounts. This does not apply to STEMC installed residential

secondaries.

6

30"

(3) 2" CONDUIT

WARNING

TAPE

CLEAN

FILL

FINAL GRADE

42"

12"

A

A'

SECTION A-A'

STANDOFF BRACKET, MACHINE BOLT, WASHER,

LOCK NUT, AND LAG SCREW PROVIDED BY STEMC

(NOT PROVIDED IF A SINGLE CONDUIT IS INSTALLED).

FRONT VIEW

SIDE

VIEW



TRENCH AND RISER DETAIL FOR 1Ø / 3Ø

PRIMARY CONDUIT INSTALLATION

JANUARY 2020 TRD

NOTES:1. Trench shall be inspected by STEMC engineering before backfilling.

2. Backfill with clean native earth and machine tamp.

3. Install string ("mule tape" preferred") with minimum rating of 2,500 lbs in conduit and cover ends to keep

out water.

4. Schedule 80 pvc conduit shall extend 10 feet above final grade, unless point of feed is an underground

device.

5. Conduit below final grade shall be pvc or hdpe (schedule 40 or 80).

6. Minimum 36 inch sweeping elbows shall be used. Rigid elbows may be required, as determined by STEMC

engineering.

7

44"

12"

27"

2" PRIMARY

FIBERGLASS TRANSFORMER PAD

STEMC PROVIDED MARKINGPOST FOR ELECTRICIAN CONNECTION

(SEE FIGURE 1).

20"

PROPERTY LINE

FRONT OF PAD

ROADSIDE

2" PRIMARY

3" SECONDARY SERVICE

3" SECON

DARY TO JU

NCTIO

N BO

X

UNGLUED CAP

6"

FIGURE 1


CON

DUIT M

ARKER WITH STEM

C STICKER

FRONT PROPERTY LINE

RESIDENTIAL / SUBDIVISIONS

BACK OF EASEMENT



FIBERGLASS PAD DETAIL FOR SINGLE PHASE(1Ø)PAD-MOUNT TRANSFORMER

JANUARY 2020PM 1P SD(UF1.FG)

NOTES:1. Transformer pad is to be centered on property line at 2 feet from back of easement.2. Conduit is to be bundled at 3/4 distance from left side of conduit opening with primary conduits on the

left and secondary conduits on the right as shown above.3. Conduits markers will be provided by STEMC to mark the secondary conduit stubs.4. Install string ("mule tape" preferred") with minimum rating of 2,500 lbs in primary conduit and cover ends to

keep out water.

8

48"

52"

33"

12"

28"

6" MIN FINAL GRADE

#4 RE-BAR

SECTION A-A'

A'A

FRONT OF PAD

CONCRETE TRANSFORMER PAD

21"


2" PRIMARY

8' GROUND ROD

STEMC PROVIDED MARKINGPOST FOR ELECTRICIANCONNECTION

(SEE FIGURE 1).

UNGLUED CAP

6"

34" CHAMFER

CON

DUIT M

ARKER WITH STEM

C STICKER

FIGURE 1

COMMERCIAL / GENERAL POWER



CONCRETE PAD DETAIL FOR SINGLE PHASE(1Ø)PAD-MOUNT TRANSFORMER

JANUARY 2020PM 1P(UF1-C)

NOTES:1. Pad shall be inspected by STEMC engineering before pouring concrete.

2. Ground beneath the transformer pad shall be leveled and thoroughly compacted.

3. The primary and secondary wire shall be positioned as shown in the drawing.

4. Install 5\8" ground rod as indicated.

5. Bond # 4 solid copper to re-bar and ground rod.

6. Fiber reinforcement can be used in lieu of re-bar.

7. The concrete's minimum 28 day compressive strength shall be 2500 psi.

8. Install string ("mule tape" preferred") with minimum rating of 2,500 lbs in primary conduit and cover ends to

keep out water.

9

PRIMARY

CONDUITS

SECTION A-A'

A'A

SECONDARY

CONDUITS

8 FT. GROUND ROD

FINAL GRADE

72" SQUARE

12"15"18"

12" 48"

4" MAXIMUM HEIGHT

ON ANY CONDUIT

#4 RE-BAR

22"

6" MIN

1 2 3

4 5 6

FRONT OF PAD

CONCRETE TRANSFORMER PAD

12"


34 CHAMFER

GROUND ROD(NOTE 3)

SERVICECONDUITS(NOTE 2)



CONCRETE PAD DETAIL FOR 75-500 kVA, THREE-PHASE(3Ø)PAD-MOUNT TRANSFORMER

JANUARY 2020PM 3P 75-500(UF3-C75-500)

NOTES:1. Pad shall be inspected by STEMC engineering before pouring concrete.2. Ground beneath the transformer pad shall be level and thoroughly compacted.3. Service conduit positions are numbered according to location preference.4. Three 5/8" x 8' copper ground rods (copperweld or equal) shall be installed; one in primary

compartment of transformer, and two on the back side of the transformer pad. a #4 copper wire shallbe installed between ground rods and attached to each ground rod with a ground rod clamp.

5. Bond #4 solid copper to rebar and ground rod.6. 3-2" primary conduit to have min. 36" radius elbows and to be extended beyond edge of pad in

direction indicated by engineering. rigid elbows may be required, as determined STEMC engineering.7. The concrete minimum 28 day compressive strength shall be 2500 p.s.i.8. Install string ("mule tape" preferred") with minimum rating of 2,500 lbs in primary conduit and cover ends

to keep out water.

10

AutoCAD SHX Text

NOT TO EXCEED 18"

#4 RE-BAR ON 18" CENTERS

9 10

7 1 2 5

6438

108" SQUARE

22" 24"

11"20"

A'A

SECTION A-A'

4" MAXIMUMHEIGHT ON ANY

CONDUIT

PRIMARYCONDUITS

SECONDARYCONDUITS

8 FT. GROUND ROD

FINAL GRADE

FRONT OF PAD

CONCRETE TRANSFORMER PAD GROUND ROD(NOTE 3)

SERVICECONDUITS(NOTE 2)

5"5"

5"

5"

5"


34 CHAMFER

24"

2"



CONCRETE PAD DETAIL FOR 750-2500 kVA,THREE-PHASE(3Ø) PAD-MOUNT TRANSFORMER

JANUARY 2020PM 750-2500

(UF3-C750-2500)

NOTES:1. Pad shall be inspected by STEMC engineering before pouring concrete.2. Ground beneath the transformer pad shall be level and thoroughly compacted.3. Service conduit positions are numbered according to location preference.4. Three 5/8" x 8' copper ground rods (copperweld or equal) shall be installed; one in primary

compartment of transformer, and two on the back side of the transformer pad. a #4 copper wire shallbe installed between ground rods and attached to each ground rod with a ground rod clamp.

5. Bond #4 solid copper to rebar and ground rod.6. 3-2" primary conduit to have min. 36" radius elbows and to be extended beyond edge of pad in

direction indicated by engineering. rigid elbows may be required, as determined STEMC engineering.7. The concrete minimum 28 day compressive strength shall be 2500 p.s.i.8. Install string ("mule tape" preferred") with minimum rating of 2,500 lbs in primary conduit and cover ends

to keep out water.

11

AutoCAD SHX Text

8" MIN

FRONT OF PAD

REQUIRED BOLLARDS

POSSIBLE ADDITIONAL

BOLLARD LOCATIONS

(AS REQUIRED BY STEMC).

BOLLARD LOCATION

SECTION A-A'

A'A

BACKFILL HOLE

WITH CONCRETE.

72"

36"

36"

18"

18"

4" DIA. STEEL POST

FILLED WITH CONCRETE.



PROTECTIVE BOLLARD DETAIL

JANUARY 2020 PBD 12

//

20'

15'

10'

10'

10'

6'

4'

4'

4'

Padmount Transformer



CLEARANCE SPECIFICATIONS FOR PAD MOUNTEDTRANSFORMERS

JANUARY 2020 PMC1

NOTES:1. Clearances from padmout transformer to structures are measured from the nearest metal portion of

the transformer to the structure or any over hang.

13

AutoCAD SHX Text

Fuel Tank

AutoCAD SHX Text

Pool

AutoCAD SHX Text

Doorway

AutoCAD SHX Text

Fire Escape

AutoCAD SHX Text

Building (Non-Combustable)

AutoCAD SHX Text

Building (Combustable)

AutoCAD SHX Text

Water Hydrant

AutoCAD SHX Text

Landscaping

AutoCAD SHX Text

Gas Meter

X

X

X X X X X

FRONT OF PAD

TRANSFORMER PAD

FENCES OR OTHER OBSTACLES

OBS

TRU

CTIO

N

OBS

TRU

CTIO

N

BUILDING

8' MIN

4' MIN

4' MIN4' MIN



CLEARANCE SPECIFICATIONS FOR PAD MOUNTEDTRANSFORMERS

JANUARY 2020 PMC2

NOTES:1. These clearances are STEMC minimums. Greater clearances may be requried by local codes, due to

building construction, type of operation, location of doors and windows, etc. Check with local inspection

authority.

14

VALLEY GUTTER

2'5.5'5'2.5'7'

℄SIDEWALKPGL=TOP OF CURB

WAT

ER

GAS

TELE

PHO

NE

(BO

TH S

IDES

)

TELE

PHO

NE

(BO

TH S

IDES

)

SEW

ERFO

RCE

MAI

N

ELEC

TRIC

42"

MIN

. CO

VERA

GE

ELEC

TRIC

42"

MIN

. CO

VERA

GE

2'

15' UTILITYEASEMENT

15' UTILITYEASEMENT50' ROW

31' B. TO B.26 PAVEMENT 5'4.5'

9.5'9.5'5' 4.5'

7'2.5'5'5.5'

STO

RMDR

AIN

AGE

SAN

ITAR

YSE

WER

VARIES

⅊⅊

IN GENERAL, ELECTRIC IS INSTALLED ALONG ONE SIDE OF THE

ROADWAY AT EVERY OTHER LOT LINE WITH SECONDARY VOLTAGE

CROSSING TO THE OTHER SIDE OF THE ROADWAY, IN SOME INSTANCES,

PRIMARY CABLE AND TRANSFORMERS WILL BE REQUIRED ON BOTH SIDES

OF THE ROADWAY. (WG 13-AUG-2013)

50' ROW WITH UTILITIES CROSS SECTIONNOT TO SCALE

PADMOUNTEDXFMR

1/4" /FT. (TYP.)

LIGH

TIN

G

2.5'


A Touchstone Energy® Cooperative TYPICAL UTILITIES CROSS SECTION JANUARY 2020 TUCS

NOTES:1. If ROW is not 50 ft, adjust distance from curb using URD Staking drawing to maintain distances from

back of easment.

15

13'

9'

15'

"STREET NAME"

PROPERTY LINE

JUNCTION BOX STAKE (IF REQUIRED)

TRANSFORMER/ HANDHOLE STAKE

BACK OF UTILITY EASEMENT

PROPERTY CORNER

CURB

PROPERTY LINE (ROW)STREET LIGHT STAKE (IF REQUIRED)

2'



UNDERGROUND ELECTRIC STAKING REQUIREMENTS

JANUARY 2020 URD STAKING

NOTES:1. Any requested street light locations shall be staked 2 feet away from the curb in line with the members

property line.

2. All junction boxes shall be staked 9 feet away from the property corner on the member's property line.

3. All transformers and handholes shall be staked 13 feet away from the property corner on the member's

property line.

4. Property line starts at edge of ROW. 50 foot ROW is typical, 25 foot from centerline of road.

16

service installation specifications...3.homeowner / electrician to install "9s" meterbase...

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