draft control -...

Draft ControlHawk integrated

CB Accu-Draft standaloneOperation, service, and parts

Manual Part No. 750-221
11/2013

Safety PrecautionsA complete understanding of this manual is requiredbefore attempting to start up, operate or maintain theequipment. The equipment should be operated only bypersonnel who have a work ing knowledge andunderstanding of the equipment.

Failure to follow these precautions may result in damageto equipment, serious personal injury, or death.

The following symbols are used throughout this manual:

! DANGERWARNING

This symbol indicates a potentiallyhazardous situation which, i f notavoided, could resul t in ser iouspersonal injury, or death.

! DANGERCAUTION

This symbol indicates a potentially hazard-ous situation which, if not avoided, couldresult in damage to the equipment.

Note: This symbol indicates informationthat is vital to the operation of thisequipment.

AbbreviationsFollowing is an explanation of the abbreviations,acronyms, and symbols used in this manual.

AC Alternating Current

AR Automatic Reset

ASME American Society of Mechanical Engineers

ASTM American Society of Testing and Materials

BHP Boiler Horsepower

BTU British Thermal Unit

C Degrees Celsius

CFH Cubic Feet per Hour

Cu Ft Cubic Feet

DC Direct Current

F Degrees Fahrenheit

FM Factory Mutual

FS Flame Safeguard

ft Feet

GPM Gallons per Minute

Hd Head

HT Height

HTB High Turndown Burner

HZ Hertz

In H2O Inches of Water

IRI Industrial Risk Insurance

Lb Pound

LWCO Low-Water Cut-Off

M Million

MFD Micro-Farad

MR Manual Reset

NEC National Electric Code

No. Number

pH Measure of the degree of acid or base of a solution

P/N Part Number

PPM Parts Per Million

PR Program Relay

psi Pounds Per Square Inch

SAE Society of Automotive Engineers

scfh Standard Cubic Feet per Hour

T Temperature

TC Temperature Control

TI Temperature Gauge

Draft ControlOperation, Maintenance and

Parts Manual

Hawk Integrated and

CB Accu-Draft Stand Alone

Please direct purchase orders for replacement manuals to your local Cleaver-Brooks authorized representative

Manual Part No. 750-221

11/2013 Printed in U.S.A.

Cleaver-Brooks 2013

TO: Owners, Operators and/or Maintenance Personnel

This operating manual presents information that will help to properly operate and care for the equipment. Study its con-tents carefully. The unit will provide good service and continued operation if proper operating and maintenance instruc-tions are followed. No attempt should be made to operate the unit until the principles of operation and all of the components are thoroughly understood. Failure to follow all applicable instructions and warnings may result in severe personal injury or death.

It is the responsibility of the owner to train and advise not only his or her personnel, but the contractors' personnel who are servicing, repairing or operating the equipment, in all safety aspects.

Cleaver-Brooks equipment is designed and engineered to give long life and excellent service on the job. The electrical and mechanical devices supplied as part of the unit were chosen because of their known ability to perform; however, proper operating techniques and maintenance procedures must be followed at all times. Although these components af-ford a high degree of protection and safety, operation of equipment is not to be considered free from all dangers and hazards inherent in handling and firing of fuel.

Any “automatic” features included in the design do not relieve the attendant of any responsibility. Such features merely eliminate certain repetitive chores, allowing more time for the proper upkeep of equipment.

It is solely the operator’s responsibility to properly operate and maintain the equipment. No amount of written instructions can replace intelligent thinking and reasoning and this manual is not intended to relieve the operating personnel of the responsibility for proper operation. On the other hand, a thorough understanding of this manual is required before at-tempting to operate, maintain, service, or repair this equipment.

Because of state, local, or other applicable codes, there are a variety of electric controls and safety devices which vary considerably from one boiler to another. This manual contains information designed to show how a basic burner operates.

Operating controls will normally function for long periods of time and we have found that some operators become lax in their daily or monthly testing, assuming that normal operation will continue indefinitely. Malfunctions of controls lead to uneconomical operation and damage to the equipment. In most cases, these malfunctions can be traced directly to care-lessness and deficiencies in testing and maintenance.

It is recommended that a boiler room log or record be maintained. Recording of daily, weekly, monthly and yearly main-tenance activities and recording of any unusual operation will serve as a valuable guide to any necessary investigation.

Most instances of major boiler damage are the result of operation with low water. We cannot emphasize too strongly the need for the operator to periodically check the low water controls and to follow good maintenance and testing practices. Cross-connecting piping to low water devices must be internally inspected periodically to guard against any stoppages which could obstruct the free flow of water to the low water devices. Float bowls of these controls must be inspected frequently to check for the presence of foreign substances that would impede float ball movement.

The waterside condition of the pressure vessel is extremely important. Waterside surfaces should be inspected frequently to check for the presence of any mud, sludge, scale or corrosion.The services of a qualified water treating company or a water consultant to recommend the proper boiler water treating practices are essential.

The operation of this equipment by the owner and the operating personnel must comply with all requirements or regu-lations of their insurance company and/or other authority having jurisdiction. In the event of any conflict or inconsistency between such requirements and the warnings or instructions contained herein, please contact Cleaver-Brooks before pro-ceeding.

DO NOT OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS YOU FULLY UNDERSTAND ALL APPLICABLE SECTIONS OF THIS MANUAL.

DO NOT ALLOW OTHERS TO OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS THEY FULLY UNDERSTAND ALL APPLICABLE SECTIONS OF THIS MANUAL.

FAILURE TO FOLLOW ALL APPLICABLE WARNINGS AND INSTRUCTIONS MAY RESULT IN SEVEREPERSONAL INJURY OR DEATH.

! DANGERWARNING

TABLE OF CONTENTSSection 1

Hawk 4000 Draft ControlIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Draft Damper Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Draft Damper Assembly Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Draft Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Control Strategy Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Initial Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Electrical Connections Hawk 4000. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Section 2Hawk 4000 Draft Control

Setup and ConfigurationEnable Draft Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Draft Control & Draft Setup Screens . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Commissioning Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Configure Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5Operating Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Section 3CB Accu-Draft: Stand-Alone Draft Control

Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Interconnection Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2System I/O List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4System Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Operation Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7Alarm Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Monitor I/O Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Section 4Parts

Draft Control Damper Bill of Material . . . . . . . . . . . . . . . . . . . . . . . . . 4-2Complete Draft Control Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2Draft Control Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3Control Panel Accu-Draft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

www.cleaverbrooks.com

Section 1

Hawk 4000 Draft ControlInstallation

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Draft Damper Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Draft Damper Assembly Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Draft Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Control Strategy Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Initial Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Electrical Connections Hawk 4000. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Section 1 — Hawk 4000 Draft Control Installation

A. IntroductionThe purpose of the Cleaver-Brooks Draft Control system is tomaintain a constant draft (pressure), throughout the firing range ofthe boiler. This is achieved by modulating the draft damper inresponse to the deviation between the measured draft and anoperator adjusted set point.

Draft Control is typically used in systems where multiple boilersshare a common stack and outlet ductwork, or in a single boilerapplication with high natural draft.

B. Draft Damper AssemblyThe Draft Damper Assembly consists primarily of the physicaldamper, connecting l inkage, modulation motor, pressuretransmitter, and pressure switch. A sample drawing for a 24”damper is shown on page 1-7. Take careful note of the direction offlow.

C. Draft Damper Assembly InstallationThe damper assembly is installed per the notes and instructionsshown on the Draft Damper Assembly drawing (see Section 4Parts).

Primary components such as the position limit switch, pressuretransmitter, and modulation motor are factory mounted on thedamper assembly.

The damper assembly torque requirement increases as the damperassembly diameter increases, requiring more powerful modulationmotors for the larger diameter dampers. This relationship is shownin Table 1-1.

There are seven (7) assemblies available based on stack diameter.

NOTE: Damper must be installed in the vertical position.

Refer to Section 4 for the Draft Damper assembly and a completeparts list.

Table 1-1 Damper Assemblies and Torque Requirements

Assembly P/N Size Torque Rating Mod Motor P/N

506-00544 12” 150 in-lb. 894-03568

506-00541 16” 150 in-lb. 894-03568

506-00543 20” 150 in-lb. 894-03568

506-00542 24” 150 in-lb. 894-03568

506-00545 32” 300 in-lb. 894-04077

506-00546 36” 535 in-lb. 894-04078

506-00547 42” 535 in-lb. 894-04078

1-2 Part No. 750-221


D. Draft Control SystemThe Draft Control System is available in two (2) versions:

• Version 1 - user-selectable option of the Hawk 4000 control system.

• Version 2 - Stand-Alone system

Both versions are pre-programmed with two (2) control strategyoptions.

E. Control Strategy OptionsFeedback Control is a direct acting, proportional + integral controlalgorithm where, in this case, stack draft is compared to a setpointvalue and any resultant error is first multiplied by a proportionalterm and then integrated based on the incremental time away fromsetpoint.

There are two (2) user selectable Draft Control Strategies:

1. Feedback control (default)2. Feedforward-Plus-Feedback control

Feedforward-Plus-Feedback control adds a secondary variable(firing rate demand) to the Feedback Control. The effect is that achange in the secondary variable pre-positions the damper tominimize the deviation between the Process Variable (PV) and theSetpoint (SP) during a load change.

Important!A L inkage Assembly w /Potentiometer kit is requiredwhen ordering a Stand -Aloneversion with a Feedforward-Plus-Feedback control strategy. The kitprovides a 0-10 VDC firing ratedemand feedforward signal basedon jackshaft position.

Part No. 750-221 1-3


F. Initial SettingsThe Pressure Transmitter p/n 817-04917 is factory calibrated atminus 4.0” W.C. to +4.0” W.C.

The Draft setpoint defaults at 0.0” W.C. and is adjustable from theoperator interface.

The range of Pressure Switch p/n 836-01130 is 0.2” W.C. to 1.0”W.C.

The Feedforward-Plus-Feedback input 4-point characterization isfactory set linearly as shown in Table 1-2.

Figure 1-1 Draft Control Components

GC52imH O

ASHCROFT

8888

Pressure TransmitterPressure Switch

Important!The actual Draft Pressure switchtrip point must be field set and itscontacts wired into the FlameSafeguard non-recycle circuit.

Table 1-2 Feedforward-Plus-Feedback input/Output

Pt. Input Output

1 0.0 0.0

2 33.0 33.0

3 66.0 66.0

4 100.0 100.0

1-4 Part No. 750-221


G. Electrical Connections Hawk 4000

Figure 1-2 Draft Control Wiring Hawk 4000

NOTE: Terminal numbers shown are typical. Applications may vary.

Part No. 750-221 1-5


Figure 1-3 Wiring Diagram Reference Drawing

(7)LLTR

(1)

103(NC)(C)

MGV-1AS

(NC)(C)

MGV-2AS

1/2 SEC.

PRI.KVA)(

4

-2

CCT

CCF-1

MC(B)

(W)

(R)

GPVV

GPV-2

-1GPV

IT

HFS(R/B) (B/B)

CAPS30

2

(LINE 20)

44 L2

L1

5

23

23

24

17

2(95)

6

5 27

27

132

(13) (14)

(NOTE 1)

14

CCF

BS

OLC HLC

MR

LWLR

LDLW

FFLR

OL BMS

ALARM

BLOWERMOTOR

10 SECONDPILOT

FLAMEDETECTION FD

BMSI

1234567891011121314151617181920212223242526

2827

293031323334353637383940414243444546474849505152535455565758596061626364656667

(5,48)

A

M

P

S1

S2

BLK

BLK

38

38

3

31

MODULATE 18182011 AUTO

(W)

LFS

DMT

(T2)24V.

RELEASE TO

SIGNALDAMPER CLOSE

SIGNALDAMPER OPEN

PROVING SWITCHDAMPER CLOSEDPROVING SWITCHDAMPER OPEN

2

D 25

12 21

X 22

COMMON

8 29

10

(R)

MANMAS

42

41

(B)

26

(R)

MAIN FUEL VALVE(S) 7

4

MFC(B)

(W)

(Y)

19 19

(R)

MDM(T1)

43

(B)

(96) (A1) (A2)

1515JUMPER

5422

(LINE 48)6 13

24

16

16

62

(FNQ-5.6)

(FNQR-2.5)

705*EDS

10

11

15

BN

30

6

13 31

14

(B) (A)PR

(44)

(6)(9)PR

47

52 52

SDHPS

54 12

(24 VAC)

14

SDOPS

43

51 (B)SDOPR

(A)4

(6)(9)SDOPR

(63)

(BLK)

(WH)

(RED)

(SHIELDED CABLE)

JPP68

67

66

SUPPLY

FIRING RATEFEEDBACK POWER

(XLP30B)

104(2 AMP)

4

24 23

(L2)(-)(12VDC)(+) (L1)

(SHIELDED CABLE)

5FUSE

(RED)

(BLK)

(SHIELDED CABLE)

(BLK) (RED)

JUMPER

5 51

38

54

52

26

SHIELDED CABLE

25

DRAFT CONTROL

5 5

(T1)(T2) (-) (+)

DAMPER MDM

24V.(L1) (L2)

4 4

RECYCLE LIMITS

NON-RECYCLE LIMITS

25

26

NOTE - GROUND SHIELDAT PANEL END ONLY.

BLK

RED (-)

(+)

STACK DAMPER PRESSURETRANSMITTER

SHIELDED CABLE

RED

20

22BLK

22

20

SCALE

34

1-6 Part No. 750-221


Part No. 750-221 1-7

Figure 1-6 Example, 24” Damper Assembly


1-8 Part No. 750-221


Section 2

Hawk 4000 Draft ControlSetup and Configuration

Enable Draft Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Draft Control & Draft Setup Screens . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Commissioning Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Configure Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5Operating Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Section 2 — Hawk 4000 Draft Control Setup and Configuration

This section covers the Draft Control option integrated into theHawk 4000 control system.

A. Enable Draft ControlTo begin setup, from Configuration Screen #1 (Figure 2-1), enableDraft Control.

After activating the Draft Control option, a Draft Control button willappear on the Screen Select Menu (Figure 2-2) Touch the button togo to the Draft Control screen. (Figure 2-3).

Figure 2-1 Configuration Screen #1

Figure 2-2 Screen Select

2-2 Part No. 750-221


B. Draft Control & Draft Setup Screens

The controls on the Draft Control screen are dedicated to the normaldaily operation of the draft control (see section E, OperatingControls below).

Initial commissioning is accomplished from the Draft Setup screen(see section C, Commissioning Controls below).

Figure 2-3 Draft Control Screen

Figure 2-4 Draft Setup Screen

Part No. 750-221 2-3


C. Commissioning ControlsHigh Stack Pressure Alarm Set

A High Stack Pressure alarm will be generated if the Stack Pressurerises above this value. The value entered here should beapproximately 0.25 to 0.5 inches WC above the operating setpointvalue. The initial operating setpoint value is 0.0” WC and theoperating setpoint range is -1.0” to 1.0” WC. (Figure 2-5).

Output LimitsThe Output Limit controls set the minimum and maximum desiredcontrol output. The minimum limit applies only when thecombustion air fan is energized, thus allowing the damper to closefully when the fan is not running. The maximum limit applies onlywhen the draft control is released for modulation, allowing thedamper to open fully during purge.

FeedforwardThe touch controls are used to enter or change the values shown inFigure 2-7, with the resulting curve used to characterize thefeedforward signal. Four (4) points are provided that construct a 3-segment curve. The output value is calculated between thesepoints. The factory setting is linear.

.

Figure 2-5 Alarm Set data

Figure 2-6 Output Limits

Figure 2-7 Feedforward

Figure 2-8

Linear setting

Damper Opens more

Damper Opens Less

Input

Output

Table 2-1 Factory Settings

Pt Input Output MoreOutput

Lessoutput

1 0.0 0.0 0 0

2 33.3 33.3 47 21

3 66.7 66.7 82 46

4 100.0 100.0 100 100

2-4 Part No. 750-221


P Gain / I Gain / D Gain The touch controls are used to enter values for the proportional gain,integral gain, and derivative gain. Adjustments to these touchcontrol Set Points tune the response of the control loop for generaloperating conditions.

Release for ModulationThe draft control can be configured to release for modulation eitherafter Purge or after Main Fuel (lightoff).

D.Configure TransmitterSets the zero and span values of the draft transmitter.

E. Operating ControlsPercent Oxygen Indication

Only visible if an O2 analyzer is installed and the O2 Analyzer optionis selected from Configuration Screen #1.

Air Pos. Feedback Indication

The Air Position Feedback signal is shown in Figure 2-13. Thisdisplay shows the position of the Combustion Air Damper. Thissignal is the feedforward input variable and is displayed forinformation only.

lStack Pressure IndicationStack pressure is shown numerically and graphically with the redvertical bar graph. The stack pressure is measured in inches watercolumn.

Figure 2-9 Tuning Parameters

Figure 2-10 Release for Modulation

Figure 2-11 Configure Transmitter

Figure 2-12 Oxygen Indicator

Figure 2-13 Feedback Indicator

Figure 2-14 Stack Pressure

Part No. 750-221 2-5


Set Point Adjust Touch ControlThe operating setpoint is adjusted using the control shown in Figure2-15. Valid inputs are between -1.0 and +1.0 IWC.

Auto/Manual Mode IndicatorShows the current operating mode.

Auto/Manual Mode Push ButtonsThe Auto/Man buttons change the operating mode. When thesystem is in manual mode, the Open/Close push buttons control theposition of the outlet damper (see below).

Output Open/Close Push buttonsThe output display shows the position (percent open) of the stackdamper.

The value displayed is the control output to the stack damperactuator. The same value is represented graphically by the white bargraph.

The Open/Close push buttons control the position of the outletdamper when in manual mode.

F. Sequence of Operation With the recycle limits closed (input I2/5 ON) and load demandpresent, the draft control output is forced to the maximum (100%),fully opening the outlet damper. With stack damper proven openswitch closed (Input I7/0 ON) and external interlock is closed (InputI2/6 ON), the combustion air blower will start and the sequenceenters the purge period. After purge is complete (or after lightoff,depending on the Release for Modulation setting), the draft controlis released for modulation.

Upon burner shutdown and completion of post purge, the draftcontrol output is forced to minimum (0%), closing the outletdamper.

Figure 2-15 Adjust SP

Figure 2-16 Mode Indicator

Figure 2-17 Mode PB

Figure 2-18 Output

2-6 Part No. 750-221


Section 3

Accu-Draft Stand-Alone Draft Control

Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Interconnection Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2System I/O List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4System Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Operation Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7Alarm Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Monitor I/O Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Section 3 — Accu-Draft Stand-Alone Draft Control

This section covers the CB Accu-Draft stand-alone draft controlsystem.

A. ControllerThe controller (Figure 3-1), or PLC, is a DIN rail mounted modularunit requiring 120 VAC power. There are two (2) communicationports, RS-232/485 and Ethernet.

The controller is equipped with the following standard I/O:

• Qty (2) analog voltage inputs, 0-10 VDC

• Qty (10) discrete inputs, 120 VAC

• Qty (6) discrete outputs, relay

In addition to the standard I/O, a 4 channel analog output expansionmodule (4-20 mA) is provided that connects to the controller viaribbon cable.

B. Interconnection Wiring DiagramRefer to Figure 3-2 for the connections between the stand-aloneDraft Control panel and the Stack Draft Damper Assembly.

Figure 3-1 Processor and Analog Output Module

3-2 Part No. 750-221


Figure 3-2 Draft Damper Electrical Connections

Part No. 750-221 3-3


C. System I/O List

D.System SetupThe Accu-Draft main menu screen is shown in Figure 3-3.

The Menu Screen provides the user access to the following areas:

• Stack Draft Control (F1)

• Monitor I/O (F2)

• Log In (F4) and Log Out (F8)

• System Setup and Panelview Configuration available upon Login

Table 3-1 System I/O List

Hardware Address Description Signal Source Type

I/0 Blower On Boiler Control System DI, 120 VAC

I/1 Main Fuel Valves Energized Boiler Control System DI, 120 VAC

I/2 High Stack Pressure Pressure Switch DI, 120 VAC

I/3 Limits Closed Boiler Control System DI, 120 VAC

I/4 Damper Open Limit Switch Damper Actuator DI, 120 VAC

I/5 Purge Boiler Control System DI, 120 VAC

I/6 Common Alarm Flame Safeguard System DI,120 VAC

O/0 Blower Start Permissive Draft Control System DO, Contact

O/1 Alarm Bell Draft Control System DO, Contact

VI/1 Stack Pressure Pressure Transmitter 0-10 VDC

VI/2 Firing Rate Feedforward Boiler Control System 0-10 VDC

Aux AO/0 Damper Actuator Output Draft Control System 4-20 mA

Figure 3-3 Main Menu

3-4 Part No. 750-221


The System Setup Menu (Figure 3-4) is password protected. Enterthe 4-digit password to access.

Three input selections are shown – Setup and Alarm Sets, FeedForward, and Exit.

Release Damper Option (F1)The Stack Damper is released to modulate either AFTER LIGHTOFF(default) or AFTER PURGE. Pressing the Touch Control F1 togglesbetween these two choices.

Press (F4) to go to Close Damper Time Delay.

Close Damper Time Delay Option (F1)The damper is automatically closed after the post purge period andthe blower motor is stopped. Pressing the (F1) key allows theoperator to enter a time delay value (Sec.) that keeps the damperopen until the delay time expires. The maximum delay time is 600Seconds (10 Min.).

Press (F4) to go to Deviation Alarm Setup.

Figure 3-4 System Setup Menu

Figure 3-5 Release Damper Options

Figure 3-6 Close Damper Time Delay Option

Part No. 750-221 3-5


Deviation Alarm Setup (F1)The System generates an alarm based on the deviation between theactual stack pressure or Process Variable (PV) and the Setpoint(SP). Set the maximum deviation limit in Inches Water Column (IN-WC) (F1), and the deviation alarm time delay in seconds (F2) fromthis screen (Figure 3-7).

Press (F4) to exit and return to the System Setup Menu.

Tuning (F2)Draft control loop tuning parameters are adjusted from the TuningScreen (Figure 3-8). The Tuning screen is accessed from the SystemSetup Menu (Figure 3-4).

Pressing either (F1) or (F2) function key from the Tuning Screendisplays a numeric keypad where a new value for either Gain orReset can be entered. The new value must be within the range of 0-25.

Firing Rate F(X) (F3)Firing Rate F(X) is an optional feature that when enabled changesthe draft control strategy from a simple feedback control loop to amore complex Feedforward-Plus-Feedback control loop. Theaddition of feedforward improves system response to loadfluctuations by effectively pre-positioning the outlet damper to theproper position for any given firing rate and in doing so, minimizingthe difference of the stack draft Process Variable (PV) from theSetpoint (SP).

The optional Firing Rate F(X) is enabled by pressing the F1 key asshown on Figure 3-9.

The DISABLED message display changes to ENABLED when F1 ispressed. Pressing F1 again disables the option.

Once ENABLED, a Firing Rate Feedforward 4-point characterizationcan be entered. Four (4) input points and four (4) output points areprovided that together construct a smooth firing rate feedforwardcurve. The input value is the Firing Rate. The output value is theoutput signal (%) to the outlet damper actuator when the measureddraft is on set point at that Firing Rate.

The factory set is linear as shown in Table 3-2 and Figure 3-10.

Figure 3-7 Alarm Setup Screen

Figure 3-8 Tuning Screen

Figure 3-9 Firing Rate

3-6 Part No. 750-221


Eight (8) screens are provided to input a new value for each input(X) point and output (Y) point, starting with Input Point #1. Tochange Point #1, press the (F1) key and enter the new value withthe pop-up numeric keypad.

Continue to set all Input and Output values to correspond to theoperating conditions.

Press (F4) to move to the next point.

This concludes System Setup.

E. Operation ScreenThe purpose of the Operation screen (Figure 3-12) is to monitorand/or control draft during periods of normal unit operation.

Feedforward Variable (FF)The current value of feedforward variable which is the unit firingrate demand signal.

Stack Draft (PV)Actual value of the stack draft in inches water column.

Control Variable (CV)The value of the signal to the draft damper.

Stack Draft Set Point (SP)Set point value in inches water column.

Control Mode (MAN/AUTO)The active operating mode is indicated with white text on a blackbackground.

Figure 3-10 Damper Response to Firing Rate.

Linear setting

Damper Opens Less

Damper Opens more

0 33 66 100

33

66

100Table 3-2 Factory Set

Pt Input Output MoreOutput

LessOutput

1 0.0 0.0 0 0

2 33.0 33.0 47 21

3 66.0 66.0 82 46

4 100.0 100.0 100 100

Figure 3-11 Firing Rate F(X) Input Screen

Figure 3-12 Operation Screen

DEC SP

[F1]

INC CV

[F6]

DEC CV

[F5]

MODE

[F3]

INC SP

[F2]

MENU

[F8]

ALARM

[F7]

TUNE

[F4]

AUTO

TUNE

[LOG IN]

##.##PV In##.##SP In

###FF Pct###CV Pct

Part No. 750-221 3-7


Stack Draft Set Point (SP)The set point value is increased by pressing the INC SP button anddecreased by pressing DEC SP. Pressing either button once changesthe set point value +/- 0.05 “.

Control Variable (CV)When the operating mode is manual the Control Variable can beincreased by pressing INC SP or decreased by pressing DEC SP.

F. Alarm ScreenAll active alarms can be viewed from the Alarm screen (Figure 3-13) which is accessible from the Operation screen by pressing (F7).

The following alarms are generated by the System:

Stack Draft Input Bad QualityStack Draft input signal is outside the range of the analog inputchannel i.e. less than 3.5 mA or greater than 20.5 mA.

PV/SP Deviation AlarmThe process variable/set point deviation is greater than a predefinedlimit value. (See Alarm Setup)

Stack Damper Proof OpenStack Damper was commanded by the System to go to the full openposition and either failed to do so or the full open limit switch isimproperly set.

Feedforward F(X) Data Entry ErrorA value entered in the Input or Output array of the Feedforward F(X)is less than the previous point’s value. To correct, make sure eachsuccessive input point is greater than the previously entered point,and each successive output point is greater than the previouslyentered point.

HIGH Stack Draft (Pressure) The alarm is triggered when the Stack Draft pressure switch detectsa HIGH pressure condition. The switch NO (Normally Open) contactis wired into the System. The NC (Normally Closed) contact is wireddirectly into the flame safeguard non-recycle limit circuit. SeeWiring Diagram

Figure 3-13 Alarm screen

3-8 Part No. 750-221


G.Monitor I/O ScreenThe Monitor I/O screen (Figure 3-14) shows on one screen thecurrent status of all of the discrete I/O wired to the System. Theprimary purpose of the screen is as a troubleshooting tool and alsoto support System startup and commissioning.

There are five (5) inputs (I/0 thru I/5) and one (1) output (O/0). Thecurrent status of each point is shown with a text message. Forexample in Figure 3-14 Blower Status is displayed as OFF andwhen the Blower starts, the text message will change to ON.

H.Sequence of Operation The following sequence of operation is only applicable when thecontrol mode is set to Automatic. In Manual mode the operator hasfull control of the stack damper at all times i.e. during boiler startup,normal operation, and shutdown.

The Sequence is started automatically whenever one of thefollowing events occurs:

1. The Burner switch is turned from the OFF position to the ONposition while the recycle limit is closed and the Flame Safeguardalarm is de-energized.

2. The recycle limit closes while the Burner switch is ON and theFlame Safeguard alarm is de-energized.

3. The Flame Safeguard alarm is reset while the Burner switch isON and the recycle limit is closed.

With the Limits input closed (I/3) and the Flame Safeguard commonAlarm input open (I/6) the Outlet Damper is driven to the full openposition. When the full open position is reached the Damper ProofOf Open limit switch closes (I/4) and the START Combustion AirBlower output is energized (O/0). The blower motor starts and thepurge cycle timer begins to time out. After the purge cycle iscomplete the Draft Control System will either:

• Release for modulation if the Release option is set to AFTER PURGE.

• Hold full open if the Release option is set to AFTER LIGHTOFF and released when the Main Fuel Valves are energized (I/1).

Upon burner shutdown and completion of post purge, the FlameSafeguard System stops the blower. The Draft Control detects thatthe blower is now off (I/0) and drives the Outlet Damper to itsminimum position (0%).

The Outlet Damper may remain open for a preset amount of timeafter the blower motor stops if required to do so. Refer to the CloseDamper Time Delay Option (Figure 3-6).

Figure 3-14 Monitor I/O Screen

Part No. 750-221 3-9


Section 4

Parts

Draft Control Damper Bill of Material . . . . . . . . . . . . . . . . . . . . . . . . . 4-2Complete Draft Control Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2Draft Control Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3Control Panel Accu-Draft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Section 4 — Parts

Figure 4-1 Draft Control Damper Bill of Material

12" 427-0037216"20"24"32"

427-00363427-00373

427-00374427-00371

Size (Dia.) P/N Item 1Panel)

506-00544506-00541

506-00542506-00545

506-00543

P/N Item 2

894-03568894-03568894-03568894-03568894-04077

P/N (Less ControlDamper Assembly

& Control Panel)Kit (Includes Damper Assy

Complete Damper Assembly

880-01879880-01880880-01881880-01882880-01883

Damper

For complete Damper Assembly with Micrologix Control Panel(Figure 4-4) use applicable 880-kit listed below.

For Damper Assembly w/o Control Panel use applicable506-Assembly listed below.

For Proper Damper Assembly sizing please refer to theVent Stack dimension for the applicable boiler model.

Notes:

36" 427-00375506-00546 894-04078TBD

Damper Assy. Mod. Motor

Figure 4-2 Complete Draft Control Kits42" 427-00376506-00547 894-04079TBD

4-2 Part No. 750-221

Section 4 — Parts

GC52imH₂O

ASHCROFT

8888

Damper Installation Notes:

Figure 4-3 Draft Control Assembly

Part No. 750-221 4-3

Section 4 — Parts

Figure 4-4 Control Panel Accu-Draft

4-4 Part No. 750-221

e-mail: [email protected]

Web Address: http://www.cleaverbrooks.com

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