750-291_OM_Profire-NTXL_May09

Manual Part No. 750-291 05/2009

Profire NTXLBurner

Light Oil, Gas, or Combination

InstallationOperation

Maintenance

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Placed on all Profire burners are warning or caution labels designed to inform the operator of potential hazardsand stress important information. These labels are shown below.

HAZARD OF ELECTRIC SHOCK !!! MORE THAN ONE DISCONNECT MAY BE RE-QUIRED TO DISCONNECT ALL POWER TO THIS PANEL. SERIOUS PERSONAL INJURY OR DEATH MAY RESULT.

READ PRODUCT MANUAL AND FULLY UNDERSTAND ITS CONTENTS BEFORE ATTEMPTING TO OPERATE THIS EQUIP-MENT. SERIOUS PERSONAL INJURY OR DEATH MAY RESULT.

TO AVOID PERSONAL INJURY FROM MOVING PARTS, SHUT OFF ALL ELEC-TRICAL POWER BEFORE SERVICING THIS EQUIPMENT.

WARNINGPROVIDE SUPPORT FOR THIS PANEL TO PREVENT DAMAGE TO THE ELEC-TRICAL COMPONENTS.

CAUTION

ONLY FACTORY AUTHORIZED BURNER SERVICE PERSONNEL SHOULD START UP, ADJUST, OR SERVICE THIS EQUIP-MENT.

CAUTIONAFTER FINAL FUEL INPUT ADJUST-MENTS ARE MADE, VERIFY FUEL IN-PUT BY METER IF POSSIBLE.

CAUTION

WARNING

WARNING

WARNING

FAILURE TO INSTALL AND OPERATE THIS EQUIPMENT IN ACCORDANCE WITH THE MANUFACTURERS RECOMMENDED INSTRUCTIONS AND INDUSTRY STANDARDS AND PRACTICES CAN RESULT IN FIRE, EXPLOSION, PROPERTY DAMAGE AND/OR PER-SONAL INJURY !! READ THIS MANUAL IN ITS ENTIRETY PRIOR TO ANY ATTEMPT TO COMMISSION THIS EQUIPMENT. INSTALLATION, STARTUP, OPERATION AND MAINTE-NANCE OF THIS EQUIPMENT MUST BE PERFORMED ONLY BY FACTORY AUTHORIZED, EXPERIENCED AND QUALIFIED PERSONEL.

iii

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

Manual Part No. 750-291

05/2009

Cleaver-Brooks 2009

CLEAVER-BROOKSProfire NTXL BurnerLight Oil, Gas, or Combination

Installation, Operation, and Maintenance Manual

NOTE: If you have a CB HAWK ICS Boiler Control System, refer to Cleaver-Brooks manual 750-229.

iv

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 afford 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 free him of certain repetitive chores and give him more time to devote to the proper upkeep of equipment.

It is solely the operators responsibility to properly operate and maintain the equipment. No amount of written instruc-tions 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 attempting 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 oper-ates.

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 and, in most cases, these conditions can be traced directly to carelessness and deficiencies in testing and maintenance.

THE INSTALLATION OF A BURNER SHALL BE IN ACCORDANCE WITH THE REGULATIONS OF AUTHORITIES HAVING JURISDICTION. THE EQUIPMENT MUST BE INSTALLED IN ACCORDANCE WITH APPLICABLE LOCAL, STATE, OR PROVINCIAL INSTALLATION REQUIREMENTS INCLUDING THE NATIONAL ELECTRIC CODE (NEC) AND ASSOCIATED INSURANCE UNDERWRITERS. WHERE APPLICABLE, THE CANADIAN GAS ASSOCIATION (CGA) B149 AND CANA-DIAN STANDARDS ASSOCIATION (CSA) B140 AND B139 (FOR OIL BURNERS) CODES SHALL PREVAIL.

OIL AND GAS BURNING EQUIPMENT SHALL BE CONNECTED TO FLUES HAVING SUFFICIENT DRAFT AT ALL TIMES TO ASSURE SAFE AND PROPER OPERATION OF THE BURNER.

DO NOT USE GASOLINE, CRANKCASE OIL, OR ANY OIL CONTAINING GASOLINE

In the event of any conflict or inconsistency between local requirements and the warnings or instructions contained in this manual, please contact Cleaver-Brooks before proceeding.

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

vMODEL DESIGNATION, SIZES AND INPUT

Model designations are based on the type of fuel(s) to be fired. Burner size is based on firing rate (maxi-mum input in Btu/hr).

MODEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FUELNTXLNG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GasNTXLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . #2 OilNTXLLG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .#2 Oil and Gas

BURNER SIZE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Gas Input Btu/hr336. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33,600,000378. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37,800,000462. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42,600,000504. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50,400,000546. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54,600,000588. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58,800,000630. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63,000,000

Gas input based on natural gas at 1,000 Btu/cu.ft. and 0.60 specific gravity

BURNER SIZE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum Oil Input U.S.G.P.H.336. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251378. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .282462. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .330504. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .360546. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .390588. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .420630. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .450

Oil input based on No.2 oil at 140,000 Btu/gal

The installation of a burner shall be in accordance with the regulations of authorities having jurisdiction. The equipment must be installed in accordance with applicable local, state or provincial installation require-ments, including the National Electric Code (NEC), and insurance underwriters. Where applicable, the Cana-dian Gas Association (CGA) and Canadian Standard Association (CSA) shall prevail.

Oil and Gas burning equipment shall be connected to flues having sufficient draft at all times, to assure safe and proper operation of the burner.

The burners are designed to burn either gas or No. 2-6 oils as defined by ASTM D396-1978 specifications. Do not use gasoline, crankcase oil, or any oil containing gasoline.

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Section 1 IntroductionGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2NT Firing Head Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Operating Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Flame Safeguard Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Combustion Air Handling System . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Firing Rate Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5Gas System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5NT Series Low NOx System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7Oil System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Section 2 InstallationElectrical Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Packing Plastic Refractory Around Oven . . . . . . . . . . . . . . . . . . . . . . . 2-2Atomizing Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Typical Oil Supply Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Circulating Oil Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Oil Pressure Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Installation Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Section 3 Sequence of OperationGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Circuit and Interlock Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Sequence of Operation Oil or Gas . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Pre-purge Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Ignition Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Run Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5Burner Shutdown Post Purge . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Flame Loss Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6No Pilot Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6Pilot But No Main Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6Loss of Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

vii

Section 4 CommissioningGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2Preparation for Initial Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Prestart Tasks and Checklist All Fuels . . . . . . . . . . . . . . . . . . . 4-3Actuator setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4Air and Fuel Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Combustion Adjustment on Gas and Oil . . . . . . . . . . . . . . . . . . . . . . . 4-7Fuel Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Burner Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Spark Pickup Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Gas Pilot Flame Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

Commissioning Boiler (gas) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Commissioning Boiler (Oil) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13Operating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

Section 5 TroubleshootingBurner Does Not Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2No Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Pilot Flame, But No Main Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Burner Stays in Low Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Shutdown Occurs During Firing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

Section 6 Inspection and MaintenanceGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2Checking Flame Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3Firing Head Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4Pilot and Ignition Electrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4Flame Scanner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5Oil Nozzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5Air Handling system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6Burner Mounting Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6Oil System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7Gas System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8Extended Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8Recommended Inspection Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

Milwaukee, Wisconsin

www.cleaver-brooks.com

Section 1Introduction

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2NT Firing Head Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Operating Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Flame Safeguard Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Combustion Air Handling System . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Firing Rate Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5Gas System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5NT Series Low NOx System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7Oil System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Section 1 Introduction

1-2 750-291

A. GeneralCB ProFire burners are assembled, wired and tested at the factory,and are constructed according to the Underwriters Laboratory code.All burners in the Profire series comply, when equipped withoptional equipment, to CSD-1, XL GAP (formerly GE GAP/IRI),Factory Mutual (FM), NFPA-85, Including the National ElectricalCode (NEC), or other insuring underwriters requirements. Whereapplicable, the Canadian Gas Association (CGA) B149 andCanadian Standards Association (CSA) B140 codes shall prevail.Other regulatory agency control options are available. Installationshould also conform to state and local codes governing suchequipment. Prior to installation, the proper authorities havingjurisdiction are to be consulted, permits obtained, etc.NTXL gas burners are of the axial flow type, based on low tomoderate swirling air jet aerodynamics. The burner uses intensivemixing with counterflow fuel injection to minimize NOX formation.All burners feature ignition by spark-ignited gas pilot flame. Witheither gas or oil, the burner operates with full modulation. A switchpermits changeover from automatic fully modulated firing tomanually set firing at any desired rate between minimum andmaximum. Additional safeguards assure that the burner alwaysreturns to minimum firing position for ignition. The ProFire XL oilburners are of the low pressure, air atomizing (nozzle) type.

The burners are designed for automatic, unattended operationexcept for periodic inspection and maintenance. After selecting theproper overload settings for the starter, the rest of the control panelcomponents require little attention except for occasional cleaning.

The operator must be familiar with the individual functioning of allcontrols to understand the operations and procedures described inthe manual. Identify and locate each item in the illustrations as theyare described in the following sections.

B. NT Firing Head DesignThe NT burner heads unique core and radially variable pitch swirlblades provide absolute flame stability at all loads.

Figure 1-1 ProFire NTXL

Figure 1-2 NT Firing Head Fuel and Air Flows

Lance Gas

Radial Air

AxialAir

Tangential Air

CenterCoreGas


750-291 1-3

The burner head is mounted inside the blast tube. The gas isdirected to the various gas paths via connecting piping.The high fuel-to-air mixing efficiency is obtained from the axial,radial and tangential turbulent air flow field generated at the burneroutlet (see Figure 1-2). This is combined with high velocity fuel jets,resulting in an optimized and well defined mixing pattern formaximum local mixture uniformity. Low NOx burners (


1-4 750-291

3. CONTROL CIRCUIT BREAKER.Supplementary low over current protection only. No larger than 15amps.

4. AUTO-MANUAL MODULATION SELECTOR SWITCH. Auto Position: Selects boiler modulation control.

Manual Position: Selects 135 ohm potentiometer for manualmodulating control

5. MANUAL MODULATING CONTROL (135 ohm)Increases or decreases the burner firing rate manually.

6. SIGNAL LAMPS.A. POWER ON (white) illuminates when the control circuit is

energized (powered).B. IGNITION (amber) illuminates when the ignition

transformer is powered, and gas pilot valve is energized (opened).

C. MAIN FUEL (green) illuminates when the main fuel valve or valves (gas or oil) are energized (open).

D. FLAME FAILURE (red) illuminates when the flame safeguard system fails to detect pilot or main flame.

Other controls included are motor starters to energize the motorsand an ignition transformer to provide a high voltage spark for pilotignition.

D.Flame Safeguard ControlAutomatically programs each starting, operating and shutdowncycle in conjunction with operating, limit, and interlock devices.This includes in timed sequence, operation of the blower motor,ignition system, fuel valves and modulating motor. The sequenceincludes air purge prior to ignition and after burner shutdown. Theflame scanner monitors the pilot, both oil and gas flames, andinstantly responds to loss of flame.

The control recycles automatically during normal operation, orfollowing a power interruption. It must be manually reset followinga safety shutdown. An internal checking circuit, effective on everystart, will prevent burner operation in the event the flame relay isheld in.

E. Combustion Air Handling SystemThe axial, radial, and tangential turbulent air flow field generated atthe burner outlet is combined with high velocity fuel jets, resultingin an optimized and well defined mixing pattern for maximum localmixture uniformity.

Figure 1-3 Control Panel (CB-Hawk ICS)

Figure 1-4 Flame Safeguard


750-291 1-5

The combustion air handling system consists of several majorcomponents:

1. Damper Assembly (Figure 1-5). A multi blade damper regulates the combustion air volume and ispositioned by an actuator receiving a signal from the boiler controlsystem. The damper is normally ALMOST CLOSED in the low fireposition and opens as the burner drives toward a high fire position.An optional second damper can be installed downstream of thecombustion air fan.

2. Motor Driven Impeller (Figure 1-6). The heart of the burner is a backward curved aluminum impeller.The diameter of the impeller determines available air pressure andthe width determines air capacity in cubic feet per minute. Alternatemotor-impeller combinations are available for 50 cycle or 60 cyclepower and for firing against either moderate or high furnacepressure. For higher altitudes and higher furnace pressures, motorand impeller combinations are determined at the factory. Theimpeller is directly driven by a 3450 rpm motor (variable speeddrive recommended).

3. Combustion Air Proving Switch A pressure sensitive switch actuated by air pressure created by theimpeller. Contacts close to prove combustion air flow.

F. Firing Rate ControlsRegardless of the fuel used, burner input is fully modulated betweenlow fire and high fire on boiler demand. Firing rate is controlled byindividual actuators for gas (2) or oil, combustion air, FGR, andblower motor VSD. Actuator positioning is configured during theburner commissioning process. Please refer to additional controlsdocumentation where appropriate. If your boiler is equipped with aCB-Hawk ICS control system, refer to CB manuals 750-229 (HawkICS) and 750-217 (Parallel Positioning).

G.Gas SystemGas is introduced into the combustion zone from a manifold througha center core zone and multiple lances in the blast tube. Firing rateis determined by the size and number of lances, by manifoldpressure and by combustion zone pressure. The firing rate isregulated by a rotary, butterfly type throttling valve at the manifoldinlet. Depending upon specific requirements, one or two safetyshutoff, motorized main gas valves are provided for installation inthe gas train upstream of the butterfly valves. Safety shutoff gasvalves are wired into the programming control to automatically openand close at the proper time in the operating sequence.

Main Gas Components

Depending upon the requirements of the regulating authority, thegas control system and gas train may consist of some, or all, of thefollowing items. A typical gas train is shown in Figure 1-7

Figure 1-5 Air Damper w/Actuator

Figure 1-6 Impeller


1-6 750-291

Gas Control Valves

Two butterfly type valves are positioned by electric actuators andcontrol the rate of flow of gas.

Main Gas Valves

Electrically operated safety shutoff valve(s) that open to admit gasto the burner. Standard burners include two motorized gas valves w/closure interlock.

Main Gas Regulator

Regulates gas train pressure to specified pressure required at inletto gas train. Input is set by main gas pressure regulator adjustment.

Main Gas Cocks

For manual shutoff of the gas supply upstream of the pressureregulator. A second shutoff cock downstream of the main gasvalve(s) provides a means of testing for leakage through the gasvalve(s).

High Gas Pressure Switch

A pressure actuated switch that remains closed when gas pressureis below a preselected setting. Should the pressure rise above thesetting, the switch contacts will open causing main gas valve(s) toclose. This switch requires manual reset after being tripped.

Low Gas Pressure Switch

A pressure actuated switch that remains closed when gas pressureis above a preselected setting. Should the pressure drop below thissetting, the switch contacts will open, causing main gas valve(s) toclose. This switch requires manual reset after being tripped.

PILOT GAS TRAINGas Pilot Valve

A solenoid valve that opens during the ignition period to admit fuelto the pilot. It closes after main flame is established.

Gas Pressure Regulator

Reduces gas pressure to that required by the pilot.

Gas Pilot Shut-off Cock

For manually closing the pilot gas supply.

OPERATIONMetered gas flows through the main gas shutoff cock, through thepressure regulator to the automatic gas valves and butterfly valvesto the gas manifold.

The butterfly gas valves modulate flow to burner input demand. Thebutterfly valves are positioned through electric actuators by a signalfrom the boiler control system. The air control damper is positionedsimultaneously by an independent actuator. The automatic gasvalve(s) cannot be energized unless the combustion air proving


750-291 1-7

switch is closed. The low and high gas pressure switches must beclosed to prove proper gas pressure.

A normally open vent valve, if required, is located between the twoautomatic gas valves. This valve is shut when the automatic gasvalves are open. When the automatic valves are closed, the ventvalve is open for venting gas to the outside, should any be present.

H.NT Series Low NOx SystemThe NTXL burner is designed to guarantee low emissions of < 9ppm NOx and < 50 ppm CO, corrected @ 3% O2, when firingnatural gas, throughout the firing range.

The burner features an induced Flue Gas Recirculation system(FGR). The flue gases of the boiler are re-circulated through theburner using the combustion air impeller to draw the exhaust gasesand mix them with incoming fresh air. An electrically actuateddamper controls the flow of FGR to fine tune the FGR/fresh air ratio.

Ducting from the stack or boiler to the burner is by others.

Figure 1-7 Main Gas Train

Figure 1-8 Pilot Gas Train

SHUTOFF COCKSHUTOFF COCK

Gas flow

PILOTSHUTOFF

COCK

(2)PILOTVALVES

REGULATOR

TO BURNER

N.O.VENTVALVE

Figure 1-9 Induced F.G.R. System


1-8 750-291

I. Oil SystemThe burner uses compressed air for atomization. Atomizing air isindependent of combustion air. The system is supplied with aseparate compressor module for mounting near the burner.

3-Way Regulating Valve

From supply, oil enters the common port of the 3-way regulatingvalve. During shutdown and purge the SSOVs are closed andupstream fuel returns to the storage tank. When firing oil, the valvesare energized/open and metered oil flows to the oil gun/nozzle.

Figure 1-10 Firing Head

Pilot Gas

Lance Gas Piping

Inner Gas Test Portand Gauge

Outer Manifold Gas Piping

Inner Core Gas

Outer Gas Test Portand Gauge

Pilot Assembly


750-291 1-9

Nozzle Assembly

The nozzle assembly consists of four main parts: body, compressionspring, swirler, and tip. The swirler is held against the nozzle tip bythe compression spring. The nozzle body has inlet ports for air andoil lines. Metered fuel oil enters the nozzle body and flows througha tube to the swirler. Oil is forced from the core of the swirler to theside ports where it meets with the atomizing air. Atomizing airenters and passes through the nozzle body to grooves in the swirler,where it mixes with fuel oil. Air/oil passes through grooves and outof the nozzle orifice in a cone of atomized oil. Proper velocity andangle of the fine spray ensures good mixing with the combustion air,providing quiet starts and excellent combustion efficiency. Whenfiring oil, the oil nozzle should be visually inspected and cleanedevery week. If continual operation is required a spare oil gun willallow for oil gun replacement for service.

Atomizing Air Proving Switch - Pressure actuated switch contactsclose when sufficient atomizing air pressure is present.The oil valvewill not open unless switch contacts are closed.

Separate Compressor Module - All burners have a burner mountedoil metering unit and a separate compressor module. The systemfunctions as follows:

Atomizing Air - Shop air is required for the atomizing air. Shop airshould be regulated to 80-90 psig and 500 ACFM. Air pressureshould be initially set to 10 psig. over the oil pressure. As oil pressureincreases the air pressure should maintain a 10 psig. differential.

OPERATIONFuel is delivered to the metering system at 50 to 100 psi. From thesupply pump, oil is delivered to the common port of a 3-wayregulating valve for transfer to the burner nozzle through thenormally closed port or back to the storage tank through thenormally open port. During pre - and post purge, oil is returned tothe tank. During normal firing, all metered oil is delivered to the oilgun/nozzle. For compressed air atomizing applications, air enters arotary vane compressor through an air cleaner where it iscompressed to atomizing pressure. Air flows from the compressor toan air-oil tank which serves the multiple purpose of dampening airpulsation, lube oil mist recovery, lube oil and atomizing air storage.

The compressor rotor is cooled and lubricated continuously by oilunder pressure from the air-oil tank. Oil vapor is extracted by a misteliminator in the upper section of the tank. Atomizing air from theupper tank section is delivered to the nozzle at a constant volume.Air pressure increases as the burner firing rate increases. Atomizingpressure may be adjusted by the valve located on the compressorair breather. The valve allows air to be bled from the tank to thecompressor inlet. Delivery rate of the fuel oil metering is controlledby the modulating motor through adjustable linkage.

Figure 1-11 Oil nozzle - spring, swirler, and tip

! CautionThe Oil gun must be allowed tocool before disassembling. Failureto follow this caution could resultin equipment damage.

Plant air/steam atomization are alter-nate atomizatiopn options. For speci-fications and requirements, contact your authorized CB representative or the factory service dept.


1-10 750-291

Figure 1-12 Oil System

Figure 1-13 Compressor for atomizing air


750-291 1-11

Figure 1-14 Dimension Diagram

SECT

ION

A-A

SCAL

E .1

5 :

1

F.G

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VIEW

C-C

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5 :

1

BURN

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OTT

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SU

PPO

RT

MO

UN

TIN

G P

LATE

S

A A

B B

CC

110.

7

83.3

137.

3

26.6

20.1

7.8

23.8

46.0

22.1

56.7

(.63

)

AIR A

TOM

IZAT

ION

IN

LET

1" N

PTAT

OM

'G. A

IR I

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T

GAS

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MAI

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T(O

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NAL

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MAI

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38.5

69.0

89.3

111.

4

19.7

5

(3.6

)

21.926

.748

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20"

x 20

" x

8"EL

ECTR

ICAL

JUN

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EXTE

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n21

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n38

.75

30

12X

12X

1 x

2 SL

OTS

12.0

6.55

35.1

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28.7

33.1

26.5

22.5

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AS I

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T 4"

NPT

(PREF

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)

26.1

38.5 4

7.8

12.0

73.9

17.6

12.0

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AIN

GAS

IN

LET

(OPT

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AL)

GAS

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OT

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T(P

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PAN

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ILO

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LET

NAT

. GAS

67.9

42.1

41.0

OIL

IN

LET

37.0

OIL

IN

LET

3/4"

NPT

WIR

ING

TRO

UG

H

BURN

ERAC

CESS

COVE

R

F.G

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ALVE

ACT

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OR

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TUAT

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ANIF

OLD

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TER

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MAN

IFO

LDG

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ALVE

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UAT

OR

LOW

PRES

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ATO

MIZ

ING

AIR

SWIT

CH

FAN

AIR

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LET

DAM

PER

(PRO

VID

ED B

Y CB

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35.0

6.55


1-12 750-291



Section 2Installation

Electrical Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Packing Insulation Around Oven . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Atomizing Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Typical Oil Supply Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2Circulating Oil Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Oil Pressure Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Installation Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Section 2 Installation

2-2 750-291

A. Electrical ConnectionElectrical power available is usually 230/460 volt, 3 phase, 60cycle or 380 volt, 3 phase, 50 cycle. Control circuit is 115 volt,single phase, 60 cycle or 115 volt, single phase, 50 cycle. Refer tothe electrical schematic diagram shipped with the burner. Powerconnections are made at the control panel. The burner is furnishedwith a burner mounted junction box and remote control panel.Wiring from the burner junction box to remote panel, panel to boilercontrols, low water controls, remote compressor motor andremotely located fuel valves is furnished by the installer.

B. InstallationLocate the burner properly. The burner is designed for operationwith the blast tube level. Do not tilt burner up or excessivelydownward. Installation of the refractory oven is shown in Figure 2-1. Securely support the burner pedestal on the floor or foundation.Allow enough clearance at the rear of the burner for the access doorto swing open for service and maintenance.

The face of the boiler and burner flange must be sealed with thegasket provided with the burner. Carefully place the gasket over thedry oven bolts before it is mounted onto the burner flange. The I.D.of the dry oven is slightly larger than the blast tube I.D. Make surethe dry oven and burner blast tube are concentric. Due to bolt holetolerances, the dry oven may have to be shifted to accomplish this.After the dry oven nuts are properly tightened, the burner and dryoven assembly can then be mounted into the boiler.

C. Packing Insulation Around OvenThe gaps between the dry oven and furnace and between the dryoven and firing tube should be packed with Superwool blanketinsulation P/N 872-01075. Apply refractory coating P/N 872-00225 to hold the insulation in place (see Figure 2-1).

D.Atomizing AirFor oil burners shop air must be provided at 80-100 psig and 500ACFM.

E. Typical Oil Supply LoopContinuous oil circulation must be supplied to the burner at a rateof 50 percent greater than the high fire burning rate. The oilcirculating pump should be located as close as possible to thestorage tank to keep suction lines short and minimize to preventsuction loss. The return line to the tank is connected at thedischarge port of the three-way regulating valve. Note that thereturn line should be a minimum of 20 inches higher than thesupply line. From supply, oil enters the common port of the 3-wayregulating valve. During shutdown and purge the SSOVs are closedand upstream fuel returns to the storage tank. When firing oil, thevalves are energized/open and metered oil flows to the oil gun/nozzle.

! CautionThe burner refractory is air-curedon ly. Hea t -cu r ing mus t beinitiated at initial start-up. Runthe burner at low fire for a periodof 6 to 8 hours before starting togradually increase the firing rate.Failure to do so will result indamage and c racks i n therefractory.


750-291 2-3

The proper strainers, check valves, vacuum and pressure gauges,etc. should be installed as indicated. An oil strainer is shipped loosewith the burner. All lines should be pressure tested after installation.

F. Circulating Oil PumpAn circulating oil pump is required to deliver fuel oil from thestorage tank to the burner at a minimum of 150% of the maximumburner firing rate. The excess oil allows a margin for piping error,viscosity changes in the fuel oil, and circulating pump wear. Correctpipe sizing is determined by circulating rate, not burner capacity.Install the pump as close to the supply tanks as possible. Suctionlift should be as low as possible. Maximum suction of 15" Hgvacuum is good practice for either light or heated heavy oil. Thestrainer should be installed in the suction line just ahead of thecirculating pump to prevent foreign material from entering thepump. Locate the strainer so it may be easily cleaned.

G.Oil Pressure RegulatorAn oil pressure regulator should be installed in the supply line, closeto the burner to regulate oil pressure. Oil pressure is 50 to 100 PSIto the 3-way regulating valve.

H.Gas PipingGas service and house piping must supply the quantity of gasdemanded by the unit at the pressure required at the burner gastrain inlet. All piping must be in strict accordance with applicablecodes, ordinances and regulations of the supplying utility. In theabsence of other codes, piping should be in accordance with thefollowing standards: "National Fuel Gas Code" NFPA No. 54, ANSINo. Z 223.1. (for Canada: the Canadian Gas Association (CGA)B149 and Canadian Standards Association (CSA) B140 codes shallprevail).

Gas train components upstream of the butterfly valve are shippedloose. These components should be mounted by the installer asclose to the butterfly valve as practical. Normally, the control trainis ordered to suit a particular code or insurance regulation - such asUnderwriters Laboratories, Inc., CGA, Factory Mutual, or GE GAP.

Arrange gas piping at the burner so that the burner is accessible forservicing without disassembly.

The gas pilot supply line must be connected upstream of the maingas regulator. If a reducing bushing is required between the housepiping and the burner piping, it should be close to the burner shut-off valve. The gas piping must be internally clean and free of foreignmaterial. Before using in service, a leak test must be performed.

I. Installation ChecklistAll burners are carefully assembled and tested at the factory, butbefore being placed in service, all connectors should again bechecked for looseness caused during shipment. Check:

Electrical terminals in the control panel and on all electrical components.

! CautionBefore opening the gas shut-offva l ves , r ead the r egu la to rinstructions carefully. open shut-off valve slowly to allow inletpressure to build up slowly in theregu la to r un t i l i t i s fu l l ypressurized. opening the shut-offvalve quickly will damage theregulator.

! CautionBefore opening the gas shut-offva l ves , r ead the r egu la to rinstructions carefully. open shut-off valve slowly to allow inletpressure to build-up slowly in theregu la to r un t i l i t i s fu l l ypressurized. opening the shut-offvalve quickly will damage theregulator.


2-4 750-291

Pipe fittings and unions.

Tubing connections.

Nuts, bolts, screws.

Before operating pumps and compressors, make certain that reservoirs are properly filled with the specific lubricant. Open all necessary oil shut-off valves. Do not run compressors or pumps without oil.

Before connecting electrical current to any component, be sure the supply voltage is the same as that specified on component nameplates

Before burner operation, be sure all motors are rotating in the correct direction.

Before firing, make sure that the refractory flame cone is properly sealed to the burner mounting flange and the boiler front plate.

NoticeFGR piping from the stack to theburner is not supplied with theburner and is installed by thecontractor.

Important!It is suggested that all FGR pipingbe sch.#40, 14 I.D. and becovered with a minimum of 2inches of insulation


750-291 2-5

Figure 2-1 Dry Oven Installation


2-6 750-291

Figure 2-2 No. 2 Oil / Atomizing Air Piping Arrangement

! CautionLubricating oil is drained from the air-oil tank before shipment.before attempting to start the burner, add oil to the recommendedlevel. fill tank with non-detergent SAE 30 oil to a level midway upthe sight glass. Remove the oil filter, fill with oil, and re-install. DoNot Overfill Tank.


750-291 2-7

Figure 2-3 Gas Piping Arrangement


2-8 750-291



Section 3Sequence of Operation

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Circuit and Interlock Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Sequence of Operation Oil or Gas . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Pre-purge Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Ignition Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Run Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5Burner Shutdown Post Purge . . . . . . . . . . . . . . . . . . . . . . 3-5

Flame Loss Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6No Pilot Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6Pilot But No Main Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6Loss of Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Section 3 Sequence of Operation

3-2 750-291

A. GeneralThis section outlines the electrical sequencing of various controlsthrough the pre-purge, ignition, run, and shutdown cycles of theburner.

The program relay establishes the sequence of operation and directsthe operation of all other controls and components to provide anoverall operating sequence.

The sequences outlined here employ specific nomenclature to aid inapplying the text to the wiring diagram.

The burner and control system are in starting condition when thefollowing conditions exist:

1. Boiler water is up to the correct level, closing the low-watercutoff switch.

2. The operating limit pressure control (steam boiler) or theoperating limit temperature control (hot water boiler) and highlimit pressure or temperature control are below their cutoffsetting.

3. All applicable limits are correct for burner operation. 4. Reset manual reset (water, fuel pressure, operating limits).

All entrance switches are closed and power is present at the lineterminals of:

1. Blower motor starter2. Air compressor motor starter (if provided)3. Oil pump motor starter (if provided)

The sequences do not attempt to correlate the action of the fuelsupply system or feedwater system except for the interlock controlsthat directly relate to the action of the program relay. Chapter 4 andChapter 6 contain operating instructions and specific information onsetting, adjusting, and troubleshooting the controls.

B. Circuit and Interlock ControlsThe burner control circuit is a two-wire system designed for 115VAC, 60 Hz, single-phase power.

The electrical portion of the boiler is made up of individual circuitswith controls that are wired in a manner designed to provide a safeworkable system. The program relay provides connection points forthe interconnection of the various circuits.

The controls used vary depending upon the fuel oil or gas and thespecific requirement of applicable regulatory bodies. Refer to theboiler wiring diagram to determine the actual controls provided. Thecircuits and controls normally used in the circuits follow and arereferred to in the following sequence of operation.

Limit Circuit

Burner switch (BS) Operating limit control (OLC) pressure or temperature High limit control (HLC) pressure or temperature

Note: The make or model of theprogram relay provided will varydepend ing upon j obspecifications. The followingsequence applies regardless ofthe make or model. Please referto the Wiring Diagram (WD) foryour specific installation.


750-291 3-3

Low-water cutoff (LWCO) Gas-oil selector switch (GOS) (Combination burner only) Low gas pressures switch (LGPS) High gas pressure switch (HGPS) Fuel valve over travel interlock circuit Main gas valve auxiliary switch (MGVAS)

Blower Motor Starter Circuit

Blower motor starter (BMS) Air compressor motor starter (ACMS) (if provided)

Running lnterlock Circuit

Blower motor starter interlock (BMSI) Combustion air proving switch (CAPS) Atomizing air proving switch (AAPS) (if provided)

Low Fire Proving Circuit

Low fire switch (LFS)

Pilot Ignition Circuit

Gas pilot valve (GPV) Ignition transformer (IT) Gas pilot vent valve (GPVV) (if provided)

Flame Detector Circuit

Flame detector (FD)

Main fuel valve circuit

Main gas valve (MGV) Main gas vent valve (MGVV) (if provided) Oil valve (OV) Main fuel valve light (FVL)

Firing Rate Circuit

Modulating damper motor (MDM) Manual-automatic switch (MAS) Manual flame control (MFC) Modulating control (MC)

High Fire Proving Circuit

High fire switch (HFS)

Running Interlock and Limit Circuit

Low oil pressure switch (LOPS) High oil temperature switch (HOTS) Auxiliary low-water cutoff (ALWCO)

To comply with requirements of insurance underwriters such asFactory Mutual (FM), Industrial Risk Insurers (IRI) or others,additional interlock devices may be used in addition to the circuitsmentioned here.


3-4 750-291

C. Sequence of Operation Oil or GasOn a combination fuel unit, the gas/oil switch must be set for theproper fuel.

The following sequence occurs with power present at the programrelay (PR) input terminals and with all other operating conditionssatisfied.

1. Pre-purge CycleWhen the burner switch (BS) is turned on, and controls wired inthe limit and fuel valve interlock circuits are closed and no flamesignal is present, the blower motor start circuit is poweredenergizing the blower motor starter (BMS). The load demand light(LDL) turns on. When firing oil, the air compressor motor starter(ACMS) (if provided) is also powered.

At the same time, the program relay signals the modulating dampermotor (MDM) to open the air damper. The damper begins to openand drives to its full open or high fire position. Opening the dampermotor allows a flow of purging air through the boiler prior to theignition cycle.

On all boilers the circuitry will include a high fire switch (HFS). Thepurpose of the switch is to prove that the modulating damper motor(MDM) has driven the damper to the open position during the pre-purge cycle.

The controls wired into the running interlock circuit must beclosed within 10 seconds after the start sequence. In the event anyof the controls are not closed at this time, or if they subsequentlyopen, the program relay will go into a safety shutdown.

At the completion of the high fire purge period, the program relaysignals the modulating damper motor (MDM) to drive the airdamper to its low fire position.

To assure that the system is in low fire position prior to ignition, thelow fire switch (LFS) must be closed to complete the low fireproving circuit. The sequence will stop and hold until themodulating damper motor (MDM) has returned to the low fireposition and the contacts of the low fire switch (LFS) are closed.Once the low fire switch is closed, the sequence is allowed tocontinue.

Note: The ignition trial cannot be started if flame or a flamesimulating condition is sensed during the pre-purge period. A safetyshutdown will occur if flame is sensed at this time.

2. Ignition CycleThe ignition transformer (IT) and gas pilot valve (GPV) are energizedfrom the appropriate pilot ignition terminal.

The pilot flame must be established and proven by the flamedetector (FD) within a 10 second period in order for the ignitioncycle to continue. If for any reason this does not happen, the systemwill shut down and safety lockout will occur.


750-291 3-5

With a proven pilot, the main fuel valve(s) (OV or MGV) is energizedand the main fuel valve light (FVL) in the panel is lighted. The mainflame is ignited and the trial period for proving the main flamebegins. It lasts 10 seconds for light oil and/or natural gas. At the endof the proving period, if the flame detector still detects main flame,the ignition transformer and pilot valve are deenergized and pilotflame is extinguished.

Note: If the main flame does not light, or goes out, the fuel valve willclose. The safety switch will trip to lock out the control. See FlameLoss Sequence below.

3. Run CycleWith main flame established, the program relay releases thedamper actuator from its low fire position to control by either themanual flame control or the modulating control, depending uponthe position of the manual-automatic switch (MAS). This allowsoperation in ranges above low fire.

With the MAS set at automatic, subsequent modulated firing will beat the command of the modulating control, which governs theposition of the fuel, air damper, and FGR actuators.

Note: Normal operation of the burner should be with the switch in theautomatic position and under the direction of the modulating control.The manual position is provided for initial adjustment of the burnerover the entire firing range. When a shutdown occurs while operatingin the manual position at other than low fire, the damper will not bein a closed position, thus allowing more air than desired to flowthrough the boiler. Excess air flow subjects the pressure vessel metaland refractory to undesirable conditions.

The burner starting cycle is now complete. The load demand light(LDL) and the FVL remain lit. Demand firing continues as requiredby load conditions.

4. Burner Shutdown Post PurgeThe burner will fire until steam pressure or water temperature inexcess of demand is generated. With modulated firing, the actuatorsshould return to their low fire positions before the operating limitcontrol (OLC) opens. When the limit control circuit is opened, thefollowing sequence occurs:

1. The main fuel valve circuit is deenergized, causing the main fuelvalve (MGV) or (OV) to close. The flame is extinguished. Thecontrol panel lights (LDL) and (FVL) are turned off. The blowermotor continues to run to force air through the boiler for the postpurge period.

! WarningThe cause for loss of flame or any other unusual condition shouldbe investigated and corrected before attempting to restart. Failureto follow these instructions could result in serious personal injuryor death.


3-6 750-291

2. The blower motor start circuit is deenergized at the end of thepost purge cycle and the shutdown cycle is complete.

3. The program relay is now ready for subsequent recycling, andwhen steam pressure or water temperature drops to close thecontacts of the operating control, the burner again goes throughits normal starting and operating cycle.

D.Flame Loss SequenceThe program relay will recycle automatically each time theoperating control closes, or after a power failure. It will lockoutfollowing a safety shutdown caused by failure to ignite the pilot, orthe main flame, or by loss of flame. Lockout will also occur if flameor flame simulating condition occurs during the pre-purge period orany time the burner switch is open.

The control will prevent start-up or ignition if limit circuit controls orfuel valve interlocks are open. The control will lock out upon anyabnormal condition affecting air supervisory controls wired in therunning interlock circuit.

1. No Pilot FlameThe pilot flame must be ignited and proven within a 10-secondperiod after the ignition cycle begins. If not proven within thisperiod, the main fuel valve circuit will not be powered and the fuelvalve(s) will not be energized. The ignition circuit is immediatelydeenergized and the pilot valve closes, the reset switch lights andlockout occurs immediately.

The blower motor will continue to operate. The flame failure lightand the alarm bell (optional) are energized 10 seconds later.

The blower motor will be deenergized. The lockout switch must bemanually reset before operation can be resumed.

2. Pilot But No Main FlameWhen the pilot flame is proven, the main fuel valve circuit isenergized. The pilot flame will be extinguished 10 seconds later.The flame detecting circuit will respond to deenergize the main fuelvalve circuit within 2 to 4 seconds to stop the flow of fuel. The resetswitch lights and lockout occurs immediately. The blower motor willcontinue to operate.

The flame failure light and alarm bell (optional) are energized 10seconds later.

! CautionThe lockout switch must be manually reset following a safetyshutdown. The cause for loss of flame or any unusual conditionshould be investigated and corrected before attempting to restart.Failure to follow these instructions could cause damage to theequipment.


750-291 3-7

The blower motor will be deenergized. The lockout switch must bemanually reset before operation can be resumed. (Refer to theprevious caution.)

3. Loss of FlameIf a flame outage occurs during normal operation and/or the flameis no longer sensed by the detector, the flame relay will trip within2 to 4 seconds to deenergize the fuel valve circuit and shut off thefuel flow. The reset switch lights and lockout occurs immediately.The blower motor continues operation. The flame failure light andalarm bell (optional) are energized 10 seconds later.

The blower motor will be deenergized. The lockout switch must bemanually reset before operation can be resumed. (Refer to theprevious caution.)

If the burner will not start, or upon a safety lockout, theTroubleshooting section should be referred to for assistance inpinpointing problems that may not be readily apparent.

The program relay has the capability to self-diagnose and to displaya code or message that indicates the failure condition. Refer to thecontrol bulletin for specifics and suggested remedies. Familiaritywith the program relay and other controls in the system can beobtained by studying the contents of the manual and this bulletin.

Knowledge of the system and its controls will make troubleshootingmuch easier. Costly down time or delays can be prevented bysystematic checks of the actual operation against the normalsequence to determine the stage at which performance deviatesfrom normal. Following a routine may possibly eliminate overlookingan obvious condition, often one that is relatively simple to correct.

Remember, a safety device, for the most part, is doing its job whenit shuts down or refuses to operate. Never attempt to circumventany of the safety features.

Prevent ive maintenance and scheduled inspection of al lcomponents should be followed. Periodic checking of the relay isrecommended to see that a safety lockout will occur underconditions of failure to ignite either pilot or main flame, or from lossof flame.


3-8 750-291



Section 4Commissioning -

Starting, Operating and AdjustmentsGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2Preparation for Initial Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Prestart Tasks and Checklist All Fuels . . . . . . . . . . . . . . . 4-3Actuator setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4Air and Fuel Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Combustion Adjustment on Gas and Oil . . . . . . . . . . . . . . . . . . . . . . . 4-7Fuel Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Burner Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Spark Pickup Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Gas Pilot Flame Adjustment . . . . . . . . . . . . . . . . . . . . . . . 4-10

Commissioning Boiler (gas) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Commissioning Boiler (Oil) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13Operating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

Section 4 Commissioning - Starting, Operating and Adjustments

4-2 750-291

A. GeneralInstructions are all based upon installation being complete and allelectrical, fuel, water and vent stack connections are made.

The operator should be familiar with the burner, boiler, and allcontrols and components. Instructions for adjusting majorcomponents are given in this Section and should be reviewed priorto firing. The wiring diagram should also have been studied, alongwith the firing sequence outlined in Section 3.

Verify supply of fuel and proper voltage. Check for blown fuses, opencircuit breakers, dropped out overloads, etc. Check reset of allstarters and controls having manual reset features. Check thelockout switch on the programmer and reset if necessary.

Check to see that water column gauge glass isolation valves are open,and that feedwater pump controls operate correctly. The boilershould be filled with water to the proper operating level using waterof ambient temperature. Be sure that treated feedwater is availableand used. In hot water applications, the entire system should befilled and vented. On a steam boiler, open the vent valve to vent airdisplaced during filling. Leave the vent valve open until the escapeof steam is noted after the burner is operating.

Check all linkage for full and free movement of the shutter andmetering valves. The check can be done by loosening the linkage atthe damper motor connecting arm and manipulating the linkage byhand.

Check for rotation of all motors by momentarily closing the motorstarter or relay. The blower impeller rotation is counter-clockwise,when viewed from the motor side of the burner. The atomizing airpump rotation is clockwise when viewed from its drive end.

! WarningI t is recommended that thestarting instructions be readcomple te l y un t i l they a rethoroughly understood, beforeattempting to operate the burner,rather than per forming eachoperation as it is read for the firsttime. Failure to follow theseinstructions could result in seriouspersonal injury or death.

! WarningPrior to firing a boiler, be sure thatdischarge piping from safetyvalves or re l ie f valves, andd i scha rge p ip ing f r om a l lblowdown and drain valves, isp iped to a SAFE po in t o fdischarge, so that emission of hotwater or steam cannot possiblycause injury. Failure to followthese instructions could result inserious personal injury or death.

Figure 4-1 Check Motor Rotation

REAR

ROTATION IS DETERMINED BY FACING THE REAR OF THE MOTOR

MOTOR ROTATION, COUNTER CLOCKWISE REFERENCE

IMPELLERBURNER AIR


750-291 4-3

B. Preparation for Initial Start-Up

1. Prestart Tasks and Checklist All Fuels

Before proceeding with system start-up and adjustment, be surethat overall installation is complete. Review the boiler Operationand Maintenance Manual carefully to verify that the boiler isproperly set up for operation. Check that all shipped-loose items(those items not installed when shipped) have been correctlyinstalled. Verify the supply of fuel. Check to make sure the burner iswired as shown on the wiring diagram. Ensure that all control wiringterminals are tight.

Complete the following checklist in preparation for system startup:

1. Confirm that the fuel and electrical connections have beencompleted in accordance with the applicable codes andinsurance requirements (if necessary), and that connectionscomply with the piping schematic and wiring diagram. A copy ofthe wiring diagram is located inside the control panel.

2. Check the combustion air fan motor for correct rotationaldirection.

3. Check that the boiler is filled with water to the proper level, andthat all circulating pumps (hot water units) are correctlyinstalled and operational.

4. A representative of the gas utility should turn on the gas. Verifythat there is proper gas pressure at the gas train, and pilot, ifthis is a gas or combination burner. See the burner specificationplate for minimum and maximum natural gas pressurerequirements. The data label is located inside the control panel.Make sure that the correct regulator and spring are installed inthe main and pilot line. With the gas train pressurized, verifythat the motorized main gas valves shut tightly, with no leakagepast these valves.

5. For oil burners confirm that the plant air supply has adequateflow and pressure to provide the correct oil atomizingrequirement.

6. Check that the flame safeguard has been properly installedinside the control panel.

7. Verify that the prestart checklist for the boiler has beenthoroughly completed.

8. Provide the following test equipment on site:

A. Combustion analyzer for O2.B. U-tube manometer, or pressure gauge, to measure gas

pressures (main and pilot).C. Inclined manometer to measure draft pressures.D. Smoke spot tester for oil fired units. (CO analyzer for gas

fired burners).E. Voltmeter.F. Thermometers and thermocouples.

Important!All work on the burner should beperformed by qualified personsknowledgeable in applicablecodes.

! CautionAttempting initial burner start-upwith insufficient knowledge of theequ ipment and s ta r t -upprocedures can result in seriousdamage to the equipment. Theoperator must be totally familiarwith the entire start-up andad jus tment p rocess be fo reattempting to operate the burner.


4-4 750-291

2. Actuator setupActuator travel will normally be factory pre-set, but should beverified before commissioning the controls. Refer to the controlmanuals and any additional manufacturers documentation. If yourboiler is equipped with CB-Hawk ICS controls, refer to CB manuals750-229 (Hawk ICS) and 750-217 (Parallel Positioning).

Before commissioning, check all actuator couplings for secureness.Ensure any set screws are tightened and/or shear pins are in place.

3. Air and Fuel ControlsThe combustion system fuel and air controls have been factoryadjusted, and the unit has been test fired before it was shipped.Regardless of preliminary adjustment and operation, it may benecessary to readjust the controls for local conditions:

The fuel flow controls may require adjustment to establish therated fuel input over the full range of firing-rate modulation.

The air controls may need to be adjusted, relative to theestablished fuel flow rates, to provide the correct amount of air forcomplete, efficient combustion.

Gas pressure to the regulator must be a minimum of 10 psig.

The inner and outer manifold pressures must be balanced toprovide a stable flame. The balancing of the inner and outermanifold gas pressures will vary somewhat, depending on altitude,weather and barometric conditions.

Fuel and air adjustments are similar on all ProFire burners, whethergas-fired, oil-fired, or combination gas/oil fired. The following topicsdescribe air and fuel flow rate adjustments, and the combustion set-point objectives for optimum combustion performance:

Air Flow ControlProFire burners incorporate a multi-blade air shutter combustion aircontrol system.

The multi-blade system consists of independent blades that can beadjusted to provide more or less combustion air throughout thefiring rate range.

The air damper is linked to the damper actuator and the damperlinkage can be adjusted to increase or decrease the air opening rate.The air damper is almost closed in the low fire position and fullyopen in high fire.

Refer to Figures 4-2 and 4-3.


750-291 4-5

Figure 4-2

NOTES1 - POSITION OF DAMPER BLADES MAY BE DETERMINED BY MARKINGS ON BLADE SHAFT'S.2 - ENSURE COUPLER SET SCREWS ARE TIGHT AT ALL TIMES.

ACTUATOR

COUPLERMOUNTINGBRACKET

SHAFTW/BEARING

656-09630


4-6 750-291

Figure 4-3

Fuel and Air Flow SettingsFuel and air flow rates can be individually adjusted at low fire andat high fire to achieve rated heat input, firing rate turndown,optimum efficiency, safe operation, and the ability to cope withenvironmental changes (including air temperature, humidity,barometric pressure,) and fuel property changes. Adjustments maybe required to meet certain environmental emissions criteria, suchas NOx or CO. Combustion adjustments also vary with specificsystem applications.

Turndown capability for oil is less than that for natural gas.Therefore, on combination fueled burners, gas turndownperformance may be restricted (or determined) by the excess air andfue l t u rndown l eve l s se t i n i t i a l l y f o r o i l combus t i on.

Excess air (O2) and unburned fuel (CO) levels in boiler flue gases areused to determine combustion efficiency and as a tool in adjusting

NOTES1 - ENSURE ALL LINKAGE HARDWARE IS SECURELY FASTENED.

ACTUATOR END VIEW

OPPOSITE END VIEW

3424

75th HOLE

FROM SHAFT5th HOLEFROM SHAFT

10

30

7.4

40

5th HOLEFROM SHAFT

4th HOLEFROM SHAFT

6th HOLEFROM SHAFT

6th HOLEFROM SHAFT

656-09628

AIR DAMPER BLADE LINKAGES

8.8

35

ACTUATOR


750-291 4-7

fuel and air inputs. The system should be adjusted to the minimumexcess air quantity that provides low levels of unburned fuel withsufficient remaining oxygen to cope with normal atmospheric andfuel related changes. Unburned fuel is measured as carbonmonoxide (CO) when burning natural gas, and smoke spots whenburning oil.

ProFire burners are capable of operating at CO levels of less than 50ppm at all firing rates. The burner should be set up and maintainedto yield smoke spot levels less than a #1 spot (ASTM D2156 Shell-Bacharach Scale) to minimize soot buildup in the boiler.

C. Combustion Adjustment on Gas and OilEfficient combustion cannot be properly judged by f lameappearance, although it may help in making preliminary settings.The proper settings of air-fuel ratios must be determined by flue gasanalysis. Combustion gas analysis indicates the air to fuel ratio andthe degree of complete combustion. Instruments are available tomeasure carbon dioxide (CO2), oxygen (O2) and carbon monoxide(CO).

1. Fuel SupplyBefore initial start-up, verify that all fuel connections are tight. Fuelsupply lines should be securely connected, correctly supported, andleak tested.

The gas train for gas-fired, or combination gas/oil, burners isprovided with the overall burner package. Configuration of theappropriate gas train is based on minimum requirementsestablished by Underwriters Laboratories/CGA and the responsibleinsurance carrier if applicable.

The pilot gas train is supplied with the burner, and is shipped loose.

Fuel oil piping for oil-fired systems is shown pictorially in Section 2(Installation). In this circuit, an oil supply line from the oil tank isconnected to the inlet port of the oil pump, and an oil return linefrom the pump circulates excess oil from the pump back to the oilsupply tank.

Before burner start-up, the two oil solenoid valves are in the closed(de-energized) position and the oil metering valve is in its mostclosed position. Under this condition (with the pump operating), oilcannot flow to the oil burner nozzle, but circulates through the 3-way oil regulating valve bypass to return line and back to the oiltank. When the flame safeguard control calls for the main flame, thetwo oil solenoid valves are electrically energized. After opening, oilflows through the nozzle at the low-fire flow rate.

2. Burner SettingsTo ensure reliable and safe burner performance, the pilot electrodesetting, diffuser location and the relative positions of the burnernozzle and diffuser components must be correctly set. These itemsare preset at the factory, but must be checked prior to placing theburner into initial service, or after conducting any service work thatmay have altered their positions.


4-8 750-291

Verify the following:

Burner drawer center tube and Firing head center tube must beconcentric and aligned for free fit of the oil gun. Even on gas onlyjobs, these two components should be carefully aligned to ensureproper gas and air delivery.

Ensure the oil nozzle is centered in the firing head center tube (andcone if equipped). Prior to closing the rear door, verify correctnozzle positioning

Figure 4-4 Firing Head Alignment

Notes:

(1) Check the spacing at these areas to ensure consistent clearances (approximately 1/8).Adjust components if required. (2) All lances should project past (or be nested within) the Blast Tube by the same amount.(3) All lance heads should be equally spaced from the Blast Tube I.D.

Blast Tube

Lance Head

Stabilizer Outer Belt

Lance Head

See Note 1

See Notes 1 & 2

See Notes 1 & 3

NoticeThe gap between the lances andthe blast tube must be consistentaround the entire inside diameterof the blast tube. Centering andconcentricity is critical for all NTburner head components.


750-291 4-9

.

3. Spark Pickup TestPrior to putting the burner into service, conduct the following test toverify that the ignition spark will not cause the flame relay to pull in.

GAS FIRED

Close the pilot and the main line manual gas valves.

Startup the burner, the burner runs through prepurge, when theburner gets to pilot trial for ignition, switch the flame safety to TESTmode. The flame signal should read zero. During the trial for pilotignition with spark only, the flame relay should not pull in (i.e. beenergized).

Upon completion of successful test, proceed to remaining start-upprocedures.

OIL FIRED

Shut off the manual oil valve and manual pilot gas valve.

Figure 4-5 Gas and Air Supply Channels, NT Burner Head (Front)

Center core stabilizer with gas ports injecting outward

Hammerhead nozzles with back flow gas design

Swirler

Figure 4-6 Gas and Air Supply Piping, NT Burner Head (Rear)

Swirler Air Supply

Center Core Air Supply

Gas Lance Air Supply

Center Core Gas Supply

Gas Lances


4-10 750-291

Startup the burner, the burner runs through prepurge, when theburner gets to pilot trial for ignition, switch the flame safety to TESTmode. The flame signal should read zero. During the trial for pilotignition with spark only, the flame relay should not pull in (i.e. beenergized).

4. Gas Pilot Flame AdjustmentThe gas pilot flame is regulated by adjusting the pressure setting ofthe gas pilot regulator. Normal setting is 18" to 20" inches of watercolumn, when the pilot is burning. The flame must be sufficient tobe proven by the flame detector and ignite the main flame. To adjustpilot gas pressure, unscrew regulator cap and turn the adjustingscrew in or out.

Although it is possible to visibly adjust the size of the pilot flame,for best accuracy obtain a DC volt or micro amp reading of the flamesignal. The flame safeguard amplifier has a meter jack for thispurpose. At initial start-up and during planned maintenance, testthe pilot flame signal, pilot turndown, and safety switch lockout.

Start and stop the burner several times to ensure proper pilot settingand reliable light off.

D.Commissioning Boiler (gas)The NT firing heads have two separate gas manifolds, (Lance GasManifold and Center Gas Manifold) and a separate butterfly valveand actuator for each manifold. The fuel pressure in each manifoldshould be near equal throughout the firing range.

Start burner and establish low fire flame. Bring boiler up tooperating temperature. Adjust the air, fuel and FGR valves to matchthe burner name plate low fire gas pressure while maintaining 5-6%O2 in the flue gas. At this point the low fire air is adjusted. Slowlybring the burner up to high fire while maintaining 4.5-5.5% O2. Setthe gas manifold pressure by adjusting the main gas regulator tomatch the burner manifold pressure listed on the burner name platefor high fire input (It is recommended that high and low fire inputsbe checked against a gas meter, if available).

! WarningIf the flame signal is strong enough (greater than zero) when doingthe spark pickup test the burner should not be operated. CallCleaver-Brooks service representative for service advice. Failure tofollow this warning could result is serious personal injury or death.

Note: Once all areas check out and are properly aligned, proceedto the next section. Do not continue if the listed areas have notbeen reviewed for accuracy.


750-291 4-11

At this time start working the burner back to low fire whilemaintaining 4.5-5% O2 and the desired NOx level (also maintainclose or equal pressures in both gas manifolds).

At the low fire operating position recheck low fire gas pressures andfuel input. Manually modulate the burner from low fire to high fireverifying combustion and smooth burner operation.

Figure 4-7 Inner and outer gas manifolds

Outer GasManifold

Inner GasManifold

Lance Gas Center Gas


4-12 750-291

At this time the high and low gas pressure switches can be set usingthe following procedure:

Low Gas Pressure Switch

Turn adjusting screw until indicator moves to a pressure settingslightly below the operating gas pressure. The control will break acircuit if pressure is below this set point. The control should befinally adjusted to prevent operation with low gas pressure, but notat a pressure so close to normal operating pressure thatunnecessary shutdowns occur.

The switch must be manually reset after tripping. To reset, allowgas pressure to rise and press the manual reset button.

High Gas Pressure Switch

Turn adjusting screw until indicator moves to a pressure settingslightly above the maximum operating gas pressure. The controlwill break a circuit if pressure exceeds this value. The controlshould be adjusted to prevent operation with excessive gaspressure, but not at a pressure so close to normal operating pressurethat unnecessary shutdowns occur.

This switch must be manually reset after tripping. To reset, allowgas pressure to drop and press the manual reset button.

Figure 4-8 Gas Train

A

A

B

AA

LOW GASPRESSURESWITCH

TOBURNER

PILOTVALVE REGULATOR PILOT

SHUTOFFCOCK

TESTOPENINGTYPICAL

HIGH GASPRESSURE

SWITCH

BURNERBUTTERFLY

VALVES

N.O.VENT

VALVEMAIN GAS

VALVEW/P.O.C.

MAINGAS

VALVE

SHUTOFFCOCK

REGULATOR

SHUTOFFCOCK


750-291 4-13

E. Commissioning Boiler (Oil)Turn the fuel selector switch to Oil. Adjust the oil pressure at thesupply pump to 80 psi. Adjust the air supply pressure to 50 psig.Start burner and establish low fire flame. Bring boiler up tooperating temperature. Adjust the air, fuel and FGR valves to matchthe burner name plate low fire oil pressure while maintaining 5-6%O2 in the flue gas. At this point the low fire air is adjusted. Slowlybring the burner up to high fire one setpoint at a time whilemaintaining 4.5-5.5% O2. Set the oil pressure by adjusting theregulator at the oil supply pump to match the burner name plate forhigh fire input.It is recommended that high and low fire inputs be checked againsta oil meter, if available.At this time start working the burner back to low fire one setpointat a time while fine tuning to maintain 4.5-5% O2 and the desiredNOx level. At the low fire operating position recheck low fire oil pressure andfuel input. Manually modulate the burner from low fire to high fireverifying combustion and smooth burner operation.Verify the various gas pressures with the information on the burnerData PlateAt this time the Atomizing Air and high and low oil pressureswitches can be adjusted using the following procedures;

Atomizing Air Pressure

Atomizing air pressure is regulated by adjusting the regulator forplant air. The air pressure is indicated by the pressure gauge at theoil gun. A minimum of 10 to 12 psi air pressure at low fire issuggested. As the firing rate increases, the air pressure alsoincreases. Air pressure will be less with light oils. If any change inatomizing air pressure is made, check ignition several times forreliable light off. Adjustments should be set to obtain reliableignition with best low and high fire combustion results.

Atomizing Air Proving Switch

The knurled nut between the switch and bellows is turned in to raisethe atomizing air pressure setting. The minimum atomizing airpressure is developed during pre- and post-purge. During pre-purge, adjust the atomizing air pressure proving switch until itbreaks the circuit. Readjust switch above this circuit break point toactuate under a condition of minimum pressure, but not so close asto cause nuisance shutdowns. Air pressure against the Bourdontube actuates two single pole, single throw mercury switches, whichwhen made completes a circuit, proving the presence of atomizingair. Since the pressure of the atomizing air is at minimum when nofuel is present at the nozzle, adjustment of the switch should bemade while the unit is purging, but not firing.

High and low oil pressure switches

Figure 4-9 Fuel Selector Switch


4-14 750-291

The high oil pressure switch is set 1-2 psig. over the maximumsystem pressure. The low oil pressure switch is set 1-2 psig. belowthe minimum system pressure.

F. OperatingNormal operation of the burner should be with the switch in theautomatic position, and with the burner firing under the direction ofthe modulating control. The manual position is provided for initialadjustment of the burner over the entire firing range. When ashutdown occurs while operating in the manual position at otherthan low fire, the damper will not be in a closed position, thusallowing more air than desired to flow through the boiler. As theresulting hot flame to cool air cycling subjects the pressure vesselmetal and refractory to undesirable stress conditions.

With the switch set at AUTO, the burner will operate on amodulating basis according to the load demand.

The burner will continue to operate with modulated firing until theoperating limit pressure or temperature is reached, unless:

The burner is manually turned OFF. A low-water condition is detected by low-water level control. The electrical or fuel supply is interrupted. The combustion air pressure, fuel pressure, or atomizing air

pressure drops below minimum level.There can be other reasons for shutdown such as motor overload,flame outages, tripped circuit breakers, blown fuses, or throughother interlock devices in the circuitry.

When the burner is shut down normally, by either the operating limitcontrol or by manually switching the burner off, the load demandlight no longer glows.

Shutdown through conditions causing safety or interlock controls toopen will actuate the flame failure light (and alarm if so equipped)and the load demand light will remain lit. The cause of this type ofshutdown will have to be located, investigated, and corrected beforeoperation can be resumed. Refer to the troubleshooting section inSection 5.

G.ShutdownWhen the operating limit control setting is reached to open thecircuit or if the burner switch is turned OFF, the followingsequence occurs.

The fuel valve is de-energized and the flame is extinguished. Thetimer begins operation and the blower motor continues running toforce air through the furnace in the post-purge period.

At the end of the programmed post-purge period, the blower motoris turned off. The timer has returned to its original starting positionand stops. The unit is ready to restart.

Important!When adjusting a burner for NOx,a combustion analyzer properlycalibrated must be used at alltimes.



Section 5Troubleshooting

Burner Does Not Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2No Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Pilot Flame, But No Main Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Burner Stays in Low Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Shutdown Occurs During Firing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

Section 5 Troubleshooting

5-2 750-291

This chapter assumes that the unit has been properly installed andadjusted, and that it has been running for some time. It is furtherassumed that the operator has become thoroughly familiar withboth burner and manual by this time. The points under eachheading are set down briefly as possible causes, suggestions orclues to simplify locating the source of trouble. Methods ofcorrecting the trouble, once it has been identified, may be foundelsewhere in this manual.

If the burner will not start or operate properly, this trouble-shootingchapter should be referred to for assistance in pinpointing problemsthat may not be readily apparent.

The program relay has the capability to self-diagnose and to displaya code or message that indicates the failure condition. Refer to thecontrol bulletin for specifics and suggested remedies.

Familiarity with the programmer and other controls in the systemmay be obtained by studying the contents of this manual.Knowledge of the system and its controls will make troubleshootingmuch easier. Costly downtime or delays can be prevented bysystematic checks of actual operation against the normal sequenceto determine the stage at which performance deviates from normal.Following a routine may possibly eliminate overlooking an obviouscondition, often one that is relatively simple to correct.

If an obvious condition is not apparent, check the continuity of thecircuits with a voltmeter or test lamp. Each circuit can be checkedand the fault isolated and corrected. Most circuitry checking can bedone between appropriate terminals on the terminal boards in thecontrol cabinet or the entrance box. Refer to the schematic wiringdiagram for terminal identification.

A. Burner Does Not Start1. No voltage at program relay power input terminals.

A. Main disconnect switch open.B. Blown control circuit fuse.C. Loose or broken electrical connection.

2. Program relay safety switch requires resetting.

3. Limit circuit not completed no voltage at end of limit circuitprogram relay terminal.

A. Pressure or temperature is above setting of operation control (Load demand light will not glow).

B. Water below required level.

1. Low-water light (and alarm horn) should indicate this con-dition.

2. Check manual RESET button, if provided, on low-water control.

C. Fuel pressure must be within settings of low pressure and high pressure switches.

! WarningTroub leshoot ing shou ld beperformed only by personnel whoare familiar with the equipmentand who have read andunderstand the contents of thismanual. Failure to follow theseinstructions could result in seriouspersonal injury or death.

! WarningDisconnect and lock out the mainpower supply in order to avoid thehazard of electrical shock. Failureto follow these instructions couldresult in serious personal injury ordeath

Section 5 Troubleshooting

750-291 5-3

4. Fuel valve interlock circuit not completed.A. Fuel valve auxiliary switch not closed.

B. No Ignition1. Lack of spark.

A. Electrode grounded or porcelain cracked.B. Improper electrode setting.C. Loose terminal on ignition cable; cable shorted.D. Inoperative ignition transformer.E. Insufficient or no voltage at pilot ignition circuit terminal.

2. Spark but no flame.A. Lack of fuel no gas pressure, closed valve, empty tank,

broken line, etc.B. Inoperative pilot solenoid.C. Insufficient or no voltage at pilot ignition circuit terminal.D. Too much air.

3. Low fire switch open in low fire proving circuit.A. Damper motor not clos

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