Page 1
Benchmark 1.5LN Low NOx Boiler
Installation, Operation and Maintenance Manual
OMM-0041_0E
GF-120
Revised: 10/18/2012
Benchmark 1.5LN Low NOx Boiler
Installation, Operation, and Maintenance
Benchmark 1.5LN
Low NOx Boiler
Modulating, Condensing,
Forced Draft, Hot Water Boiler
1,500,000 BTU/H Input
Applicable for Serial N umb er s:
G-12-1953 and above.
USER MANUAL
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 1 of 166
Page 2
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
Technical Support:
1-800-526-0288
www.aerco.com
Installation, Operation and Maintenance Manual
(Mon–Fri, 8am-5pm EST)
Disclaimer
The information containe d in this manual is subject to c hange without notice from AERCO Inter national,
Inc. AERCO makes no warranty of any kind with respect to this material, including but not limited to
implied warranties of merchantability and fitness f or a particular application. AERCO International is not
liable for errors appearing in this manual. Nor for incidental or consequential damages occurring in
connection with the furnishing, performance, or use of this material.
Page 2 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
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Benchmark 1.5LN Low NOx Boiler
Installation, Operation and Maintenance Manual
OMM-0041_0E
GF-120
Table of Contents
CHAPTER 1. SAFETY PRECAUTIONS ............................................................................... 9
1.1 WARNINGS & CAUTIONS ..................................................................................................................... 9
1.2 EMERGENC Y SHUTDOWN ................................................................................................................. 10
1.3 PROLONGED SHUTDOWN ................................................................................................................. 10
CHAPTER 2. INSTALLATION .............................................................................................13
2.1 INTRODUCTION ................................................................................................................................... 13
2.2 RECEIVING THE UNIT ......................................................................................................................... 13
2.3 UNPACKING ......................................................................................................................................... 13
2.4 SITE PREPARATION. .......................................................................................................................... 14
2.4.1 Installation Clearances .................................................................................................................. 14
2.4.2 Setting the Unit .............................................................................................................................. 15
2.5 SUPPLY AND RETURN PIPING .......................................................................................................... 16
2.6 CONDENSATE DRAIN ......................................................................................................................... 16
2.6.1 Exhaust Manifold Condensate Drain ............................................................................................. 17
2.7 GAS SUPPLY PIPIN G .......................................................................................................................... 18
2.7.1 Gas Supply Specifications. ............................................................................................................ 19
2.7.2 Manual Gas Shutoff Valve ............................................................................................................. 19
2.7.3 External Gas Supply Regulator ..................................................................................................... 19
2.7.4 IRI Gas Train Kit ............................................................................................................................ 20
2.8 AC ELECTRICAL POWER WIRING ..................................................................................................... 20
2.8.1 Electrical Power Requirements ..................................................................................................... 21
2.9 MODES OF OPERATION AND FIELD CONTROL WIRING ................................................................ 22
2.9.1 Constant Setpoint Mode ................................................................................................................ 22
2.9.2 Indoor/Outdoor Reset Mode .......................................................................................................... 22
2.9.3 Boiler Management System Mode ................................................................................................ 23
2.9.4 Remote Setpoint and Direct Drive Modes ..................................................................................... 23
2.9.5 Combination Mode ......................................................................................................................... 23
2.10 I/O BOX CONNECTIONS ................................................................................................................... 24
2.10.1 OUTDOOR SENSOR IN (1) ...................................................................................................... 24
2.10.2 AIR TEMP. SENSOR (2) ........................................................................................................... 25
2.10.3 ANALOG IN (3) .......................................................................................................................... 25
2.10.4 B.M.S. (PWM) IN (4) .................................................................................................................. 25
2.10.5 SHIELD (5) ................................................................................................................................. 26
2.10.6 mA OUT (6) ................................................................................................................................ 26
2.10.7 RS-485 COMM (7) ..................................................................................................................... 26
2.10.8 TxD, RxD (8) .............................................................................................................................. 26
2.10.9 VFD/BLOWER (9) ....................................................................................................................... 26
2.10.10 EXHAUST SWITCH IN (11) .................................................................................................... 26
2.10.11 INTERLOCKS (10, 12) ........................................................................................................... 26
2.10.12 FAULT RELAY (13) .................................................................................................................. 27
2.10.13 AUXILIARY RELAY CONTACTS (14) ..................................................................................... 27
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Installation, Operation and Maintenance Manual
2.12 FLUE GAS VENT INSTALLATION ..................................................................................................... 27
2.13 COMBUSTION AIR ............................................................................................................................. 28
2.13.1 Combustion Air From Outside the Building ................................................................................. 28
2.13.2 Combustion Air From Inside The Building ................................................................................... 28
2.13.3 Sealed Combustion ..................................................................................................................... 28
2.13.4 Temporary Combustion Air Filtering During Construction ........................................................... 28
2.14 BENCHMAR K PUM P R EL A Y OPTION .............................................................................................. 29
CHAPTER 3. CONTROL PANEL OPERATION ..................................................................31
3.1 INTRODUCTION ................................................................................................................................... 31
3.2 CONTROL PANEL DESCRIPTION ...................................................................................................... 31
3.3 CONTROL PANEL MENUS .................................................................................................................. 35
3.3.1 Menu Processing Procedure ......................................................................................................... 35
3.4 OPERATING MENU ............................................................................................................................. 36
3.5 SETUP MENU ....................................................................................................................................... 37
3.6 CONFIGURATION MENU .................................................................................................................... 38
3.7 TUNING MENU ..................................................................................................................................... 40
3.8 COMBUSTION CAL MENU .................................................................................................................. 40
3.9 START SEQUENCE ............................................................................................................................. 41
3.10 START/STOP LEVELS ....................................................................................................................... 45
CHAPTER 4. INITIAL START-UP .......................................................................................47
4.1 INITIAL START-UP REQUIREMENTS ................................................................................................. 47
4.2 TOOLS AND INSTRUMENTATION FOR COMBUSTION CALIBRATION .......................................... 47
4.2.1 Tools & Instrumentation ................................................................................................................. 48
4.2.2 Installing Gas Supply Manometer .................................................................................................. 48
4.1.1Accessing the Vent Probe Port ....................................................................................................... 49
4.3 RSI REGULATOR SAFE TEST ............................................................................................................ 49
4.4 NATURAL GAS COMBUSTION CALIBRATION .................................................................................. 51
4.5 UNIT REASSEMBLY ............................................................................................................................ 56
4.6 OVER-TEMPERATURE LIMIT SWITCHES ......................................................................................... 56
4.6.1 Digital Alarm Switch Checks and Adjustments .............................................................................. 57
CHAPTER 5. MODE OF OPERATION ................................................................................61
5.1 INTRODUCTION ................................................................................................................................... 61
5.2 INDOOR/OUTDOOR RESET MODE ................................................................................................... 61
5.2.1 Reset Ratio .................................................................................................................................... 61
5.2.2 Building Reference Temperature ................................................................................................... 61
5.2.3 Outdoor Air Temperature Sensor Installation ................................................................................ 61
5.2.4 Indoor/ Outdoor Startup ................................................................................................................. 61
5.3 CONSTANT SETPOINT MODE ........................................................................................................... 62
5.3.1 Setting the Setpoint ....................................................................................................................... 62
5.4 REMOTE SETPOINT MODES ............................................................................................................. 63
5.4.1 Remote Setpoint Field Wiring ........................................................................................................ 63
5.4.2 Remote Setpoint Startup ............................................................................................................... 64
Page 4 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
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Benchmark 1.5LN Low NOx Boiler
Installation, Operation and Maintenance Manual
OMM-0041_0E
GF-120
5.5 DIRECT DRIVE MODES....................................................................................................................... 64
5.5.1 Direct Drive Field Wiring ................................................................................................................ 65
5.5.2 Direct Drive Startup ....................................................................................................................... 65
5.6 BOILER MANAGEMENT SYSTEM (BMS) ........................................................................................... 65
5.6.1 BMS External Field Wiring ............................................................................................................. 66
5.6.2 BMS Setup and Startup ................................................................................................................. 66
5.7 COMBINATION CONTROL SYSTEM (CCS) ....................................................................................... 66
5.7.1 Combination Control System Field Wiring ..................................................................................... 67
5.7.2 Combination Control System Setup and Startup ........................................................................... 67
CHAPTER 6. SAFETY DEVICE TESTING ..........................................................................69
6.1 TESTING OF SAFETY DEVICES ......................................................................................................... 69
6.2 LOW GAS PRESSURE FAULT TEST .................................................................................................. 69
6.3 HIGH GAS PRESSURE TEST ............................................................................................................. 70
6.4 LOW WATER LEVEL FAULT TEST ..................................................................................................... 71
6.5 WATER TEMPERATURE FAULT TEST .............................................................................................. 71
6.6 INTERLOCK TESTS ............................................................................................................................. 73
6.6.1 REMOTE INTERLOCK .................................................................................................................. 73
6.6.2 DELAYED INTERLOCK ................................................................................................................ 73
6.7 FLAME FAULT TESTS ......................................................................................................................... 73
6.8 AIR FLOW FAULT TESTS .................................................................................................................... 75
6.9 SSOV PROOF OF CLOSURE SWITCH ............................................................................................... 76
6.10 PURGE SWITCH OPEN DURING PURGE ........................................................................................ 76
6.11 IGNITION SWITCH OPEN DURING IGNITION ................................................................................. 77
6.12 SAFETY PRESSURE RELIEF VALV E TEST ..................................................................................... 78
CHAPTER 7. MAINTENANCE ............................................................................................79
7.1 MAINTENANCE SCHEDULE ............................................................................................................... 79
7.2 IGNITER-INJECTOR ............................................................................................................................ 80
7.3 FLAME DETECTOR ............................................................................................................................. 82
7.4 COMBUSTION CALIBRATION & RSI REGULATOR ADJUSTMENT ................................................. 82
7.4.1 RSI Regulator Pressure ................................................................................................................. 82
7.5 SAFETY DEVIC E TESTING ................................................................................................................. 85
7.6 BURNER ASSEMB LY INSPECTION ................................................................................................... 85
7.7 CONDENSATE DRAIN TRAP .............................................................................................................. 88
7.8 SHUTTING THE BOILER DOWN FOR AN EXTENDED PERIOD OF TIME ....................................... 89
7.9 PLACING THE BOI LE R BAC K IN SERVICE AFTER A PROL ON G ED SH UTDOWN ......................... 90
CHAPTER 8. TROUBLE SHOOTING GUIDE .......................................................................91
8.1 INTRODUCTION ................................................................................................................................... 91
8.2 ADDITIONAL FAULTS WITHOUT SPECIFIC FAULT MESSAGES .................................................. 101
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 5 of 166
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Installation, Operation and Maintenance Manual
CHAPTER 9. RS232 COMMUNICATION .......................................................................... 105
9.1 INTRODUCTION ................................................................................................................................. 105
9.1.1 Aquiring the PuTTY Applic ation ................................................................................................... 105
9.1.2 Logging on to a Remote Machine Using PuTTY ......................................................................... 105
9.1.3 Running a Command on a Remote Machine Using PuTTY ........................................................ 106
9.2 RS232 COMMUNICATION SETUP .................................................................................................... 107
9.3 MENU PROCESSING UTILIZING RS232 COMMUNICATION .......................................................... 107
9.4 DATA LOGGING ................................................................................................................................. 108
9.4.1 Fault Log ...................................................................................................................................... 108
9.4.2 Operation Time Log ..................................................................................................................... 108
9.4.3 Sensor Log .................................................................................................................................. 109
APPENDIX A: MENU ITEM DESCRIPTIONS 111
APPENDIX B: STARTUP, STATUS AND FAULT MESSAGES 118
APPENDIX C: SENSOR TEMPERATURE RESISTANCE 121
APPENDIX D: INDOOR/OUTDOOR RESET RATIO CHART S 122
APPENDIX E: BOILER DEFAULT SETTINGS 126
APPENDIX F: PART AND DIMENSIONAL DRAWINGS 129
APPENDIX G: PIPING DRAWINGS 145
APPENDIX H: WIRING SCHEMATICS 151
APPENDIX I: RECOMMENDED PERIODI C T ESTI NG CHECK L IST 157
APPENDIX J: BENCHMARK CONTROL PANEL FEATURES 159
APPENDIX K: RECOMMENDED SPARE PARTS LISTS 161
LIMITED WARRANTY: Benchmark Gas-Fired Boiler 163
Page 6 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
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OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
GF-120
Foreword
Installation, Operation and Maintenance Manual
Foreword
The AERCO Benchmark 1.5LN Boiler is a modulating unit. It represents a true industry advance
that meets the needs of today's energy and environmental concerns. Designed for application in
any closed loop hydronic system, the Benchmark's modulating capability relates energy input
directly to fluctuating system loads. The Benchmark 1.5, with its 20:1 turn down ratio and
condensing capability, provides extremely high efficiencies and makes it ideally suited for
modern low temperature, as well as, conventional heating systems.
The Benchmark 1.5 operates at inputs ranging from 75,000 BTU/hr. to 1,500,000 BTU/hr. The
output of the boiler is a function of the unit’s firing rate and return water temperature. Output
ranges from 74,250 BTU/hr. to 1,450,000 BTU/hr., depending on operating conditions.
When installed and operated in accordance with this Instruction Manual, the Benchmark 1.5
Boiler complies with the NOx emission standards outlined in:
South Coast Air Quality Management Distr ic t (SCAQMD), Rule 1146.2
Whether used in singular or modular arrangements, the Benchmark 1.5 offers the maximum
flexibility in venting with minimum installation space requirements. The Benchmark's advanced
electronics are available in several selectable modes of operation offering the most efficient
operating methods and energy management system integration.
For service or parts, contact your local sales representative or AERCO INTERNATIONAL.
NAME:
ORGANIZATION:
ADDRESS:
TELEPHONE:
INSTALLATION DATE: _____________________________________________
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Benchmark 1.5LN Low NOx Boiler
GF-120
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GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
CHAPTER 1
SAFETY PRECAUTIONS
Installation, Operation and Maintenance Manual
CHAPTER 1. SAFETY PRECAUTIONS
1.1 WARNINGS & CAUTIONS
Installers and operating personnel MUST, at all times, observe all safety regulations. The
following warnings and cautions are general and must be given the same attention as specific
precautions included in these instructions. In addition to all the requirements included in this
AERCO Instruction Manual, the installation of units MUST conform with local building codes, or,
in the absence of local codes, ANSI Z223.1 (National Fuel Gas Code Publication No. NFPA-54).
Where ASME CSD-1 is required by local jurisdiction, the installation must conform to CSD-1.
Where applicable, the equipment shall be installed in accordance with the current Installation
Code for Gas Burning Appliances and Equipment, CSA B149.1, and applicable Provincial
regulations for the class; which should be carefully followed in all cases. Authorities having
jurisdiction should be consulted before installations are made.
IMPORTANT
This Instruction Manual is an integral part of the product and must
be maintained in legible condition. It must be given to the user by
the installer and kept in a safe place for future reference.
WARNING
MUST BE OBSERVED TO PREVENT SERIOUS INJURY.
WARNING
BEFORE ATTEMPTING TO PER-FORM ANY MAINTENANCE
ON THE UNIT, SHUT OFF ALL GAS AND ELECTRICAL INPUTS
TO THE UNIT.
WARNING
THE EXHAUST VENT PIPE OF THE UNIT OPERATES UNDER
A POSITIVE PRESSURE AND THERE-FORE MUST BE
COMPLETELY SEALED TO PREVENT LEAKAGE OF
COMBUSTION PRODUCTS INTO LIVING SPACES.
WARNING
A DOUBLE-POLE SWITCH MUST BE INSTALLED ON THE
ELECTRICAL SUPPLY LINE OF THE UNIT. THE SWITCH MUST
BE INSTALLED IN AN EASILY ACCESSIBLE POSITION TO
QUICKLY AND SAFELY DISCONNECT ELECTRICAL SERVICE.
DO NOT AFFIX SWITCH TO UNIT SHEET METAL
ENCLOSURES.
WARNING
DO NOT USE MATCHES, CANDLES, FLAMES, OR OTHER
SOURCES OF IGNITION TO CHECK FOR GAS LEAKS.
WARNING
FLUIDS UNDER PRESSURE MAY CAUSE INJURY TO
PERSONNEL OR DAMAGE TO EQUIPMENT WHEN
RELEASED. BE SURE TO SHUT OFF ALL INCOMING AND
OUTGOING WATER SHUTOFF VALVES. CAREFULLY
DECREASE ALL TRAPPED PRESSURES TO ZERO BEFORE
PERFORMING MAINTENANCE.
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 9 of 166
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Benchmark 1.5LN Low NOx Boiler
Installation, Operation and Maintenance Manual
GF-120
OMM-0041 0E
MANUAL GAS SHUTOFF VALVE
VALVE OPEN
VALVE CLOSED
CHAPTER 1
SAFETY PRECAUTIONS
ELECTRICAL VOLTAGES UP TO 120 VAC MAY BE USED IN
THIS EQUIPMENT. THEREFORE T HE COVER ON THE UNIT’S
POWER BOX (LOCAT ED BEHIND THE FRONT PANEL DOO R)
MUST BE INSTALLED AT ALL TIMES, EXCEPT DURING
MAINTENANCE AND SERVICING.
Must be observed to prevent equipment damage or loss of
operating effectiveness.
Many soaps used for gas pipe leak testing are corrosive to metals.
The piping must be rinsed thoroughly with clean water after leak
checks have been completed.
DO NOT use this boiler if any part has been under water. Call a
qualified service technician to inspect and replace any part that
has been under water.
WARNING
CAUTIONS
CAUTION
CAUTION!
1.2 EMERGENCY SHUTDOWN
If overheating occurs or the gas supply fails to shut off, close the manual gas shutoff valve
(Figure 1-1) located external to the unit.
IMPORTANT
The Installer must identify and indicate the location of the
emergency shutdown manual gas valve to operating personnel.
1.3 PROLONGED SHUTDOWN
After prolonged shutdown, it is recommended that the startup procedures in Chapter 4 and the
safety device test procedures in Chapter 6 of this manual be performed, to verify all systemoperating parameters. If there is an emergency, turn off the electrical power supply to the
AERCO boiler and close the manual gas valve located upstream the unit. The installer must
identify the emergency shut-off device.
Figure 1-1: Manual Gas Shutoff Valve
Page 10 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
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GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
CHAPTER 1
SAFETY PRECAUTIONS
IMPORTANT – FOR MASSACHUSETTS INSTALLATIONS ONLY
Boiler Installations within the Commonwealth of Massachusetts
must conform to the following requirements:
• Boiler must be installed by a plumber or a gas fitter who is licensed within the
Commonwealth of Massachusetts.
• Prior to unit operation, the complete gas train and all connections must be leak tested
using a non-corros ive s oap .
• If a glycol solution is used as anti-freeze protection, a backflow preventer must be installed
upstream of the Fill/Makeup Valve.
• The vent termination must be located a minimum of 4 feet above grade level.
• If side-wall venting is used, the installation must conform to the following requirements
extracted from 248 CMR 5.08 (2):
(a) For all side wall horizontally vented gas fueled equipment installed in every dwelling,
building or structure used in whole or in part for residential purposes, including those owned or
operated by the Commonwealth and where the side wall exhaust vent termination is less than
seven (7) feet above finished grade in the area of the venting, including but not limited to decks
and porches, the following requirements shall be satisfied:
Installation, Operation and Maintenance Manual
1. INSTALLATION OF CARBON MONOXIDE DETECTORS. At the time of installation
of the side wall horizontal vented gas fueled equipment, the installing plumber or
gasfitter shall observe that a hard wired carbon monoxide detector with an alarm and
battery back-up is installed on the floor level where the gas equipment is to be installed.
In addition, the installing plumber or gasfitter shall observe that a battery operated or
hard wired carbon monoxide detector with an alarm is installed on each additional level
of the dwelling, building or structure served by the side wall horizontal vented gas fueled
equipment. It shall be the responsibility of the property owner to secure the services of
qualified licensed professionals for the installation of hard wired carbon monoxide
detectors.
a. In the event that the side wall horizontally vented gas fueled equipment is
installed in a crawl space or an attic, the hard wired carbon monoxide detector
with alarm and battery back-up may be installed on the next adjacent floor level.
b. In the event that the requirements of this subdivision can not be met at the
time of completion of installation, the owner shall have a period of thirty (30) days
to comply with the above requirements; provided, however, that during said thirty
(30) day period, a battery operated carbon monoxide detector with an alarm shall
be installed.
2. APPROVED CARBON MONOXIDE DETECTORS. Each carbon monoxide detector
as required in accordance with the above provisions shall comply with NFPA 720 and be
ANSI/UL 2034 listed and IAS certified.
3. SIGNAGE. A metal or plastic identification plate shall be permanently mounted to the
exterior of the building at a minimum height of eight (8) feet above grade directly in line
with the exhaust vent terminal for the horizontally vented gas fueled heating appliance or
equipment. The sign shall read, in print size no less than one-half (1/2) inch in size,
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CHAPTER 1
SAFETY PRECAUTIONS
"GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUCTIONS".
4. INSPECTION. The state or local gas inspector of the side wall horizontally vented
gas fueled equipment shall not approve the installation unless, upon inspection, the
inspector observes carbon monoxide detectors and signage installed in accordance with
the provisions of 248 CMR 5.08(2)(a)1 through 4.
(b) EXEMPTIONS: The following equipment is exempt from 248 CMR 5.08(2)(a)1 through 4:
1. The equipment listed in Chapter 10 entitled "Equipment Not Required To Be Vented"
in the most current edition of NFPA 54 as adopted by the Board; and
2. Product Approved side wall horizontally vented gas fueled equipment installed in a
room or structure separate from the dwelling, building or structure used in whole or in
part for residential purposes.
(c) MANUFACTURER REQUIREMENTS - GAS EQUIPMENT VENTING SYSTEM
PROVIDED. When the manufacturer of Product Approved side wall horizontally vented gas
equipment provides a venting system design or venting system components with the equipment,
the instructions provided by the manufacturer for installation of the equipment and the venting
system shall include:
1. Detailed instructions for the installation of the venting system design or the venting
system components; and
2. A complete parts list for the venting system design or venting system.
(d) MANUFACTURER REQUIREMENTS - GAS EQUI PMENT VENTING SYSTEM NOT
PROVIDED. When the manufacturer of a Product Approved side wall horizontally vented gas
fueled equipment does not provide the parts for venting the flue gases, but identifies "special
venting systems", the following requirements shall be satisfied by the manufacturer:
1. The identification of each "special venting system" shall include the listing of either
the website, phone number or manufacturer’s address where the venting system
installation instructions can be obtained, and
2. The "special venting systems" shall be Product Approved by the Board, and the
instructions for that system shall include a parts list and detailed installation instructions.
(e) A copy of all installation instructions for the Product Approved side wall horizontally vented
gas fueled equipment and all the venting instructions, parts lists and/or design instructions for
the venting system shall remain with the appliance or equipment at the completion of the
installation.
_______________ [End of Extracted Information From 248 CMR 5.08 (2)__________________
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Installation, Operation and Maintenance Manual
CHAPTER 2
INSTALLATION
CHAPTER 2. INSTALLATION
2.1 INTRODUCTION
This Chapter provides the descriptions and procedures necessary to unpack, inspect and install
the AERCO Benchmark 1.5 Boiler. Brief descriptions are also provided for each available mode
of operation. Detailed procedures for implementing these modes are provided in Chapter 5.
2.2 RECEIVING THE UNIT
Each Benchmark 1.5 System is shipped as a single crated unit. The shipping weight is
approximately 1551 pounds. The unit must be moved with the proper rigging equipment for
safety and to avoid equipment damage. The unit should be completely inspected for evidence of
shipping damage and shipment completeness at the time of receipt fr om the carrier and before
the bill of lading is signed.
NOTE
AERCO is not responsible for lost or damaged freight.
Each unit has a Tip-N-Tell indicator on the outside of the crate. This indicates if t he unit has
been turned on its side during shipment. If the Tip-N-Tell indicator is tripped, do not sign for the
shipment. Note the information on the carrier’s paperwork and request a freight claim and
inspection by a claims adjuster before proceeding. Any other visual damag e to the packaging
materials should also be made clear to the delivering carrier.
2.3 UNPACKING
Carefully unpack the unit taking care not to damage the unit enclosure when cutting away
packaging materials
A close inspection of the unit should be made to ensure that there is no evidence of damage not
indicated by the Tip-N-Tell indicator. The freight carrier should be notified immediately if any
damage is detected.
IMPORTANT
After unpacking, take off the unit top panel and remove the strap and
packing material at the top of the heat exchanger. The packing material is
located in the area of the ignitor-injector and staged ignition solenoid on the
burner assembly.
The following accessories come standard with each unit and are either packed separately within
the unit’s packing container or are factory installed on the boiler:
• Pressure/Temperature Gauge
• Spare Spark Ignitor-Injector
• Spare Flame Detector
• ASME Pressure Relief Valve
• Condensate Drain Trap
• 1-1/2” Gas Supply Shutoff Valve
When ordered, optional accessories may be packed separately, packed within the boiler
shipping container, or may be installed on the boiler. Any standard or optional accessories
shipped loose should be identified and stored in a safe place until ready for installation or use.
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Benchmark 1.5LN Low NOx Boiler
GF-120
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24"
4" HIGH PAD*
REAR
FRONT
44.5"
18"
101"
79"
30" 24"
24"
*(SEE NOTE IN PARAGRAPH 2.4.2)
CHAPTER 2
INSTALLATION
Installation, Operation and Maintenance Manual
2.4 SITE PREPARATION.
Ensure that the site selected for installation of the Benchmark 1.5 Boiler includes:
• Access to AC Input Power at 120 VAC, 1-Phase, 60 Hz @ 20
• Access to Natural Gas line at a minimum pressure of 4 inches W.C.
2.4.1
Installation Clearances
The unit must be installed with the prescribed clearances for service as shown in Figure 2-1.
The minimum clearance dimensions, required by AERCO, are listed below. However, if Local
Building Codes require additional clearances, these codes shall supersede AERCO’s
requirements. Minimum acceptable clearances required are:
• Sides: 24 inches
• Front : 24 inches
• Rear: 30 inches
• Top: 18 inches
All gas piping, water piping and electrical conduit or cable must be arranged so that t hey do not
interfere with the removal of any panels, or inhibit service or maintenance of the unit.
Figure 2-1: Benchmark 1.5 Boiler Clearances
KEEP THE UNIT AREA CLEAR AND FREE FROM ALL
COMBUSTIBLE MATERIALS AND FLAMMABLE VAPORS OR
LIQUIDS.
Page 14 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
While packaged in the shipping container, the boiler must be
moved by pallet jack or forklift from the FRONT ONLY.
FOR MASSACHUSSETTS ONLY:
For Massachusetts installations, the boiler must be installed by a
plumber or gas fitter who is licensed within the Commonwealth of
Massachusetts. In addition, the installation must comply with all
requirements specified in Chapter 1 (Safety Precautions), pages
11 and 12.
WARNING
CAUTION
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Installation, Operation and Maintenance Manual
CHAPTER 2
INSTALLATION
2.4.2 Setting the Unit
The unit must be installed on a 4 inch to 6 inch housekeeping pad (see NOTE below) to ensure
proper condensate drainage. If anchoring the unit, refer to the dimensional drawings in
Appendix F for anchor locations. Two lifting tabs are provided at the top of the heat exchanger.
Figure 2-2 shows the location of the tab on the top-left side. The second tab is locat ed on the
top-right side of the heat exchanger. USE THESE TW O TABS TO LIFT AND MOVE THE UNIT .
Remove the top panel from the unit to provide access to the lifting tabs. Remove the four (4) lag
screws securing the unit to the shipping skid. Lift the unit of f the shipping skid and positi on it on
the 4 inch to 6 inch housekeeping concrete pad (required) in the desired location.
NOTE:
When using the AERCO Condensate Neutralizer Tank for proper
condensate drainage, the Neutralizer Tank must be stored in a pit, O R the
boiler and AERCO Condensate Trap must be elevated higher than 4”
above the floor. See Condensate Tank instructions in TID-0074 for details.
WARNING
WHEN LIFTING OR MOVING THE BOILER:
• DO NOT MANIPULATE THE BOILER USING THE GAS TRAIN OR
BLOWER
• WHEN USING THE LIFTING TABS, ENSURE THERE IS NO LOAD
PLACED ON THE GAS TRAIN OR BLOWER
In multiple unit installations, it is important to plan the position of each unit in advance. Sufficient
space for piping connections and future service/maintenance requirements must also be taken
into consideration. All piping must include ample provisions for expansion.
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Figure 2-2: Partial Top View Showing Lifting Tab Location
Page 16
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BOILER SUPPLY
3" – 150# FLANGED
CONNECTION
BOILER RETURN
3" – 150# FLANGED
CONNECTION
1-1/2”
GAS INLET
CONNECTION
SHELL DRAIN
VALVE
EXHAUST
MANIFOLD
REAR VIEW
CHAPTER 2
INSTALLATION
Installation, Operation and Maintenance Manual
If installing a Combination Control Panel (CCP) system, it is important to identify the
Combination Mode Boilers in advance and place them in the proper physical location. Refer to
Chapter 5 for information on Combination Mode Boilers.
2.5 SUPPLY AND RETURN PIPING
The Benchmark 1.5 Boiler utilizes 3” 150# flanges for the water system supply and return piping
connections. The physical location of the supply and return piping connections are on the rear of
the unit as shown in Figure 2-3. Refer to Appendix F, Drawing AP-A-832 for additional
dimensional data.
Figure 2-3: Supply and Return Locations
2.6 CONDENSATE DRAIN
The Benchmark 1.5 Boiler is designed to condense water vapor from the flue products.
Therefore, the installation must have provisions for suitable condensate drainage or collection.
The condensate drain pipe located on the exhaust manifold (Figure 2-4) must be connected t o a
condensate trap which is packed separately within the unit’s shipping container.
The procedure to install and connect the condensate drain is provided in paragraph 2.6.1.
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Installation, Operation and Maintenance Manual
EXHAUST
MANIFOLD
PARTIAL REAR VIEW
CONDENSATE DRAIN
CONNECTION
BOILER
RETURN
CHAPTER 2
INSTALLATION
Figure 2-4: Condensate Drain Connection Location
2.6.1 Exhaust Manifold Condensate Drain
The exhaust manifold drain pipe connection shown in Figure 2-4, must be connected to a
condensate drain trap external to the unit.
NOTE
There are two different types of condensate traps that may be used in; an
older style without built-in adapter, and a newer style with a built-in adapter
(see Figure 2-5). Installation is the same (1/4” threads are inside built-in
adapter on newer style).
Refer to Figure 2-5 and install the trap as follows:
Install 3/4” NPT nipples in the tapped inlet and outlet of the condensate trap (part no. 1.
24060).
Install a third 3/4” NPT nipple in the tapped condensate outlet of the exhaust manifold. 2.
Connect the exhaust manifold nipple to the condensate trap inlet using a female union. 3.
install a suitable support under the condensate trap and ensure that the trap is level. 4.
Connect a length of 1” I.D. polypropylene hose (part no. 91030) to the nipple on the 5.
outlet side of the condensate trap and secure it with a hose clamp.
Route the hose on the trap outlet to a nearby floor drain. 6.
If a floor drain is not available, a condensate pump can be used to remove the condensate to
drain. The maximum condensate flow rate is 20 GPH. The condensate drain trap, associated
fittings and drain lines must be removable for routine maintenance.
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CHAPTER 2
INSTALLATION
Installation, Operation and Maintenance Manual
Figure 2-5: Condensate Trap Installation: Older (l eft) and Newer (right) Style
2.7 GAS SUPPLY PIPING
The AERCO Benchmark 1.5 Gas Components and Supply Design Guide, GF-4030 must be
consulted prior to designing or installing any gas supply piping.
WARNING
NEVER USE MATCHES, CANDLES, FLAMES OR OTHER
SOURCES OF IGNITION TO CHECK FOR GAS LEAKS.
Many soaps used for gas pipe leak testing are corrosive to metals.
There-fore, piping must be rinsed thor oughly with clean water after
leak checks have been completed.
NOTE
All gas piping must be arranged so that it does not interfere with
removal of any covers, inhibit service/maintenance, or restrict
access between the unit and walls, or another unit.
A 1-1/2 inch gas inlet connection is located on the rear of the unit as shown in Figure 2-3.
Prior to installation, all pipes should be de-burred and internally cleared of any scale, metal
chips or other foreign particles. Do Not install any flexible connectors or unapproved gas
fittings. Piping must be supported from the floor, ceiling or walls only and must not be supported
by the unit.
A suitable piping compound, approved for use with natural gas, should be used. Any excess
must be wiped off to prevent clogging of components.
To avoid unit damage when pressure testing gas piping, isolate the unit from the gas supply
piping. At no time should the gas pressure applied to the unit exceed 14” W.C. Leak test all
external piping thoroughly using a soap and water solution or suitable equivalent. The gas
piping used must meet all applicable codes.
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CHAPTER 2
INSTALLATION
2.7.1
The gas supply input specifications to the unit for Natural Gas are as follows:
2.7.2
A manual shut-off valve must be installed in the gas supply line upstream of the Boiler as shown
in Figure 2-6. Maximum allowable gas pressure to the Boiler is 14” W.C.
2.7.3
For Massachusetts installations, a mandatory external gas supply regulator must be positioned
as shown in Figure 2-6. The gas supply regulator must be properly vented to outdoors. Consult
the local gas utility for detailed requirements concerning venting of the the supply gas regulator.
Gas Supply Specifications.
• The maximum static pressure to the unit must not exceed 14” W.C.
• The gas supply pressure to the unit must be of sufficient capacity to provide 1500 cfh
while maintaining the gas pressure at 4.0 inches W.C. for FM, or 4.2 inches W.C. for IRI
gas trains.
Manual Gas Shutoff Valve
NOTE
Paragraph 2.7.3 applies only to bolier installations within the
Commonwealth of Massachusetts.
External Gas Supply Regulator
NOTE
The external regulator must be capable of regulating 1,500,000
BTU/HR of natural gas while maintaining a gas pressure of 4.0”
W.C. to the boiler.
CAUTION
A lock-up style regulator MUST be used when gas supply
pressure will exceed 14” W.C.
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NATURAL
GAS
SUPPLY
DIRT
TRAP
1-1/2” MANUAL
GAS SHUTOFF
VALVE
GAS PRESSURE
REGULATOR
(REQUIRED FOR
MASSACHUSETTS
INSTALALTIONS
ONLY)
CHAPTER 2
INSTALLATION
Installation, Operation and Maintenance Manual
Figure 2-6: Manual Gas Shut-Off Valve Location
2.7.4 IRI Gas Train Kit
The IRI gas train is an optional gas train configuration which is required in some areas for code
compliance or for insurance purposes. The IRI gas train is factory pre-piped and wired. See
Appendix F, Drawing AP-A-830 for details.
2.8 AC ELECTRICAL POWER WIRING
The AERCO Benchmark 1.5 Electrical Power Wiring Guide, GF-4060, must be consulted prior
to connecting any AC power wiring to the unit. External AC power connections are made to the
unit inside the Power Box on the front panel of the unit. Remove the front door of the unit to
access the Power Box mounted directly above the Control Box. Loosen the four Power Box
cover screws and remove cover to access the AC terminal connections inside the Power Box
(Figure 2-7).
NOTE
All electrical conduit and hardware must be installed so that it
does not interfere with the removal of any unit covers, inhibit
service/maintenance, or prevent access between the unit and
walls or another unit.
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UPPER RIGHT CORNER OF FRONT PANEL
TERMINAL BLOCK
GND
NEU
L1
120 VAC, 1 PHASE
CHAPTER 2
INSTALLATION
Figure 2-7: AC Input Terminal Block Location
2.8.1 Electrical Power Req u irem ent s
The AERCO Benchmark 1.5 Boiler accepts 120 VAC, single-phase, 60 Hz @ 20 A. The Power
Box contains a terminal block as shown in Figure 2-8. In addition, a wiring diagram showing the
required AC power connections is provided on the front cover of the Power Box.
Each Benchmark 1.5 Boiler must be connected to a dedicated electrical circuit. NO OTHER
DEVICES SHOULD BE ON THE SAME ELECTRICAL CIRCUIT AS THE BENCHMARK
BOILER.
A double-pole switch must be installed on the electrical supply line in an easily accessible
location to quickly and safely disconnect electrical service. DO NOT attach the switch to sheet
metal enclosures of the unit.
After placing the boiler in service, the ignition safety shutoff device must be test ed. If an exter nal
electrical power source is used, the installed boiler must be electrically bonded to ground in
accordance with the requirements of the authority having jurisdiction. In the absence of such
requirements, the installation shall conform to National Electrical Code (NEC), ANSI/ NFPA 70
and/or the Canadian Electrical Code (CEC) Part I, CSA C22.1 Electrical Code.
For electrical power wiring diagrams, see the AERCO Benchmark 1. 5 Electrical Power Wiring
Guide, (GF-4060).
Figure 2-8: AC Terminal Block Configurations
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Installation, Operation and Maintenance Manual
2.9 MODES OF OPERATION AND FIELD CONTROL WIRING
The Benchmark 1.5 Boiler is available in several different modes of operation. While each unit
is factory configured and wired for its intended mode, some additional field wiring may be
required to complete the installation. This wiring is typically connected to the Input/Output (I/O)
Box located on the lower portion of the unit front panel (Figure 2-9) behind the removable front
door.
To access the I/O Box terminal strips shown in Figure 2-10, loosen the four cover screws and
remove the cover. All field wiring is installed from the rear of the panel by routing the wires
through one of the four bushings provided.
Refer to the wiring diagram provided on the cover of t he I/O Box (Figure 2-10) when making all
wiring connections.
Brief descriptions of each mode of operation, and their wiring requirements, are provided in the
following paragraphs. Additional information concerning field wiring is provided in paragraphs
2.9.1 through 2.9.9. Refer to Chapter 5 for detailed information on the available modes of
operation.
Figure 2-9: Input/Output (I/O) Box Location
2.9.1 Constant Setpoint Mode
The Constant Setpoint Mode is used when it is desired to have a fixed setpoint that does not
deviate. No wiring connections, other than AC electrical power connections, are required for
this mode. However, if desired, fault monitoring or enable/disable interlock wiring can be
utilized (see paragraphs 2.9.9.1 and 2.9.10).
2.9.2
This mode of operation increases supply water temperature as outdoor temperatures decrease.
An outside air temperature sensor (AERCO Part No. 122790) is req uired. The sensor MUST
BE wired to the I/O Box wiring terminals (see Figure 2-10). Refer to paragraph 2.10.1 for
additional information on outside air temperature sensor installation.
Page 22 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Indoor/Outdoor Reset Mode
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CHAPTER 2
INSTALLATION
2.9.3 Boiler Management System Mode
NOTE
BMS Model 168 can utilize either pulse width modulation (PWM)
or RS485 Modbus signaling to the Boiler. BMS II Model 5R5-384
can utilize only RS485 signaling to the Boiler.
When using an AERCO Boiler Management System (BMS), the field wiring is connected
between the BMS Panel and each Boiler’s I/O Box terminal strip (Figure 2-10). Twisted shielded
pair wire from 18 to 22 AWG must be utilized for the connections. The BMS Mode can utilize
either pulse width modulation (PWM) signaling, or RS485 Modbus signaling. For PWM
signaling, connections are made from the AERCO Boiler Management System to the B.M.S.
(PWM) IN terminals on the I/O Box terminal strip. For RS485 Modus signaling, connections are
made from the BMS to the RS485 COMM terminals on the I/O Box terminal strip. Polarity must
be maintained and the shield must be connected only at the AERCO BMS. The boiler end of the
shield must be left floating. For additional instructions, refer to Chapter 5, paragr aph 5.6 in this
manual. Also, refer to GF-108M, BMS -Operations Guide.
2.9.4
The Benchmark 1.5 Boiler can accept several types of signal formats from an Energy
Management System (EMS), Building Automation System (BAS) or other source, to control
either the setpoint (Remote Setpoint Mode) or air/fuel valve position (Dir ect Drive Mode) of the
Boiler. These formats are:
While it is possible to control a boiler or boilers using one of the previously described modes of
operation, it may not be the method best suited for the application. Prior t o selecting one of
these modes of operation, it is recommended that you consult with your local AERCO
representative or the factory for the mode of operation that will work best with your application.
For more information on wiring the 4 to 20 mA / 1to 5VDC or the 0 to 20 mA / 0 to 5 VDC, see
paragraph 2.9.3.
2.9.5
Remote Setpoint and Direct Drive Modes
• 4 to 20 mA/1 to 5 VDC
• 0 to 20 mA/0 to 5 VDC
• PWM – (Pulse W idth Modulated signal. See para. 2.10.4)
• Network (RS485 Modbus. See para. 2.10.7)
Combination Mode
NOTE
Only BMS Model 168 can be utilized for the Combination Mode,
not the BMS II (Model 5R5-384).
With a Combination Mode unit, field wiring is between the unit’s I/O Box wiring terminals, the
CCP (Combination Control Panel), and the BMS (Boiler Management System). The wiring must
be accomplished using twisted-shielded pair wire from 18 to 22 AWG. Polarity must be
maintained. For further instructions and wiring diagrams, refer to the GF-108 Boiler
Management System Operations Guide and the CCP-1 data sheet.
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Installation, Operation and Maintenance Manual
Figure 2-10. I/O Box Terminal Locations and Functions
2.10 I/O BOX CONNECTIONS
The types of input and output signals and devices to be connected to the I/O Box terminals
shown in Figure 2-10 are described in the following paragraphs.
NOTE
Older I/O PCBs are wired the same as new ones, even if silk-screen
designations may slightly differ.
NOTE
DO NOT make any connections to the I/O Box terminals labeled “NOT
USED”. Attempting to do so may cause equipment damage.
2.10.1
An outdoor air temperature sensor (AERCO Part No. 122790) will be required primarily for the
Indoor/Outdoor reset mode of operation. It can also be used with another mode if it is desired to
use the outdoor sensor enable/disable feature. This feature allows the boiler to be enabled or
disabled based on the outdoor air temperature.
The factory default for the outdoor sensor is DISABLED. To enable the sensor and/or select an
enable/disable outdoor temperature, see the Configuration menu in Chapter 3.
OUTDOOR SENSOR IN (1)
The outdoor sensor may be wired up to 200 feet from the boiler. It is connected to the
OUTDOOR SENSOR IN and SENSOR COMMON terminals in the I/O Box (see Figures 2-9 and
2-10). Wire the sensor using a twisted shielded pair wire from 18 to 22 AWG. There is no
polarity to observe when terminating these wires. The shield is to be connected only to the
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Installation, Operation and Maintenance Manual
CHAPTER 2
INSTALLATION
terminals labeled SHIELD in the I/O Box. The sensor end of the shield must be left free and
ungrounded.
When mounting the sensor, it must be located on the North side of the building where an
average outside air temperature is expected. The sensor must be shielded from direct sunlight
as well as impingement by the elements. If a shield is used, it must allow for free air circulation.
2.10.2
The Air Temperature Sensor is connected to the positive (+) and negat ive (-) terminal s of the
AIR TEMP. SENSOR on the I/O board. This sensor measures the temperature of the air input to
the Air/Fuel Valve. This temperature reading is one of the components used to calculate the
rotational speed of the blower used in the combustion Calibration process (Chapter 4).
The AIR TEMP. SENSOR terminals can be used to add an additional temperature sensor for
monitoring purposes. This input is always enabled and is a view-onl y input that can be seen in
the Operating Menu. The sensor must be wired to the positive (+) and negative (-) terminals of
the AIR TEMP. SENSOR and must be similar to AERCO BALCO wire sens or Part No. 12449.
A resistance chart for this sensor is provided in Appendix C.
2.10.3
The ANALOG IN + and – terminals are used when an external signal is used to drive the air/fuel
valve position (Direct Drive Mode) or change the setpoint (Remote Setpoint Mode) of the Boiler.
Either a 4 to 20 mA /1 to 5 VDC or a 0 to 20 mA / 0 to 5 VDC signal may be used to vary the
setpoint or valve position. The factory default setting is for 4 to 20 mA / 1 to 5 VDC, however this
may be changed to 0 to 20 mA / 0 to 5 VDC using the Configuration Menu described in Chapter
3. If voltage rather than current is selected as the drive sig nal, a DIP switch must be set on the
PMC Board located inside the Control Box. Contact the AERCO factory for information on
setting DIP switches.
All of the supplied signals must be floating (ungrounded) signals. Connections between the
signal source and the Boiler’s I/O Box must be made using twisted shielded pair wire fr om 18 to
22 AWG, such as Belden 9841 (see Figure 2-10). Polarity must be maintained. The shield
must be connected only at the source end and must be left floating (not connected) at the
Boiler’s I/O Box.
AIR TEMP. SENSOR (2)
ANALOG IN (3)
Regardless of whether voltage or current is used for the drive signal, they are linearly mapped
to a 40°F to 240°F setpoint or a 0% to 100% valve position. No scaling for these signals is
provided.
2.10.4
These terminals are used to connect the AERCO Boiler Management System (BMS) to the unit.
The BMS utilizes a 12 millisecond, ON/OFF duty cycle. This duty cycle is Pulse Width
Modulated (PWM) to control valve position. A 0% valve position = a 5% ON pulse and a 100%
valve position = a 95% ON pulse.
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B.M.S. (PWM) IN (4)
Only BMS Model 168 can utilize Pulse Width Modulation (PWM),
not the BMS II (Model 5R5-384).
NOTE
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INSTALLATION
2.10.5 SHIELD (5)
The SHIELD terminals are used to terminate any shields used on sensor wires connected to the
unit. Only shields must be connected to these terminals.
Installation, Operation and Maintenance Manual
IMPORTANT
DO NOT USE the mA OUT output to remotely monitor Setpoint, Outlet
Temp or Fire Rate Out.
2.10.6
These terminals provide a 4 to 20 mA output to the VFD ( if so equipped) to control the rotational
speed of the blower. This function is enabled in the Configuration Menu (Chapter 3, Table 3-4).
2.10.7
These terminals are used for RS-485 MODBUS serial communication between the unit and an
external “Master” such as a Boiler Management System (BMS), Energy Management System
(EMS), Building Automation System (BAS) or other suitable device.
2.10.8
These terminals provide a parallel connection to the connector on the C -More Controller front
panel, for connecting a computer or laptop.
2.10.9
These terminals provide a 0 to 10 volt output to control t he rotational speed of the blower. This
function is enabled in the Configuration Menu (Chapter 3, Table 3-4).
2.10.10
These terminals permit an external exhaust switch to be connected to the exhaust manif old of
the boiler. The exhaust switch should be a normally open type switch (such as AERCO Part No.
123463) that closes (trips) at 500°F.
mA O UT (6)
RS-485 COMM (7)
TxD, RxD (8)
VFD/BLOWER (9)
EXHAUST SWITCH IN (11)
2.10.11
The unit offers two interlock circuits for interfacing with Energy Management Systems and
auxiliary equipment such as pumps or louvers. These interlocks are called the Remote Interlock
and Delayed Interlock (Figure 2-10). The wiring terminals for these interlocks are located inside
the I/O Box on the unit front panel. The I/O Box cover contains a wiring diag ram which shows
the terminal strip locations for these interlocks (REMOTE INTL’K IN and DELAYED INTL’K IN).
Both interlocks, described below, are factory wired in the closed position.
2.10.11.1 REMOTE INTERLOCK IN (10)
The remote interlock circuit is provided to remotely start (enable) and stop (disable) the Boiler, if
desired. The circuit is labeled REMOTE INTL’K IN and is located inside the I/O Box on the front
panel. The circuit is 24 VAC and is factory pre-wired in the closed (jumpered) position.
Page 26 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
INTERLOCKS (10, 12)
Both the Delayed Interlock and Remote Interlock MUST be in the
closed position to allow the unit to fire.
NOTE
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CHAPTER 2
INSTALLATION
2.10.11.2 DELAYED INTERLOCK IN (12)
The delayed interlock is typically used in conjunction with the auxiliary relay described in
paragraph 2.11. This interlock circuit is located in the purge section of the start string. It can be
connected to the proving device (end switch, flow switch etc.) of an auxiliary piece of equipm ent
started by the Boiler’s auxiliary relay. The delayed interlock must be closed for the boiler to fire.
If the delayed interlock is connected to a proving device that r equires time to close (make), a
time delay (Aux Start On Dly) that holds the start sequence of the boiler long enough for a
proving switch to make can be programmed. Should the proving switch not prove within the
programmed time frame, the boiler will shut down. T he Aux Start On Dly can be programmed
from 0 to 120 seconds. This option is locate in the Configuration Menu (Chapter 3, Table 3-4).
2.10.12
FAULT R ELAY (13)
The fault relay is a single pole double throw (SPDT) relay having a normally open and normally
closed set of relay contacts that are rat ed for 5 amps at 120 VAC and 5 am ps at 30 VDC. The
relay energizes when any fault condition occurs and remains energized until the fault is cleared
and the CLEAR button is depressed. The fault relay connections are shown in Figure 2-10.
2.10.13
AUXILIARY RELAY CONTACTS (14)
Each Boiler is equipped with a single pole double throw (SPDT) relay that is energized when
there is a demand for heat and de-energized after the demand for heat is satisf ied. The relay is
provided for the control of auxiliary equipment, such as pumps and louvers, or can be used as a
Boiler status indictor (firing or not firing). Its contacts are rated for 120 VAC @ 5 amps. Refer to
Figure 2-10 to locate the AUX RELAY terminals for wiring connections.
2.11 FLUE GAS VENT INSTALLATION
The minimum allowable vent diameter for a single Benchmark 1.5 Boiler is 6 inches.
The AERCO Benchmark Venting and Combustion Air Guide, GF-2050, must be consulted
before any flue gas vent or inlet air venting is designed or inst alled. U/L listed, posit ive pressur e,
watertight vent materials as specified in AERCO’s GF-2050, must be used for safety and code
compliance. Since the unit is capable of discharging low temper ature exhaust gases, horizontal
sections of the flue vent system must be pitched back to the unit a minimum of 1/4 inch per foot
to avoid condensate pooling and allow for proper drainage.
The combined pressure drop of vent and combustion air systems must not exceed 140
equivalent feet of 6 inch ducting. Fittings as well as pipe leng ths must be calculated as part of
the equivalent length.
For a natural draft installation the draft must not exceed ±0.25 inch W.C. These factors must be
planned into the vent installation. If the maximum allowable equivalent lengths of piping are
exceeded, the unit will not operate properly or reliably.
For Massachusetts boiler installations, the Heatfab Division of the Selkirk Corporation provides
vent systems which conform to all applicable requirements within the Commonwealth of
Massachusetts. Contact information for this supplier is as follows:
Selkirk Corporation
Heatfab Division ( www.heat-fab.com
130 Industrial Blvd.
Turners Falls, MA 01376
Phone: 1-800-772-0739
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)
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Installation, Operation and Maintenance Manual
2.12 COMBUSTION AIR
The AERCO Benchmark Venting and Combustion Air Guide, GF-2050 MUST be consulted
before any flue or combustion supply air venting is designed or implemented. Combustion air
supply is a direct requirement of ANSI 223.1, NFPA-54, CSA B149.1 and local codes. These
codes should be consulted before a permanent design is determined.
The combustion air must be free of chlorine, halogenated hydrocarbons, or other c hemicals that
can become hazardous when used in gas-fired equipment. Common sources of these
compounds are swimming pools, degreasing compounds, plastic processing and refrigerants.
Whenever the environment contains these types of chemicals, combustion air must be supplied
from a clean area outdoors for the protection and longevity of the equipment.
The AERCO Benchmark 1.5 Boiler is UL listed for 100% sealed combustion. It can also be
installed using room air, provided there is an adequate supply. (See par agraph 2.13.3 for more
information concerning sealed combustion air). If the sealed combustion air option is not being
used, an inlet screen will be attached at the air inlet on the top of the unit
The more common methods of supplying combustion air are outlined below. For more
information concerning combustion air, consult the AERCO Benchmark Venting and
Combustion Air Guide, GF-2050.
2.12.1
Air supplied from outside the building must be provided through two permanent openings. Each
opening must have a free area of not less than one square inch for each 4000 BTU/H boiler
input. The free area must take into account r estrictions such as louvers and bird screens. For
Canada installations, refer to the requirements specified in CSA B149.1-10, 8.4.1 and 8.4.3.
2.12.2
When combustion air is provided from within the building, it must be supplied through two
permanent openings in an interior wall. Each opening must have a free area of not less than
one square inch per 1000 BTU/H of total boiler input . The free area must take into ac count any
restrictions such as louvers.
2.12.3
The AERCO Benchmark 1.5 Boiler is UL listed for 100%-sealed combustion. For sealed
combustion installations, the screen on the air inlet duct of the unit must be removed. The inlet
air ductwork must then be attached directly to the unit’s air inlet.
In a sealed combustion air application, the combustion air ducting pressure losses must be
taken into account when calculating the total maximum allowable venting run. See the AERCO
Benchmark Venting and Combustion Air Guide, GF-2050. When using the boiler in a sealed
combustion air configuration, each unit must have a minimum 6 inch diameter connection at the
unit.
Combustion Air From Outside the Building
Combustion Air From Inside The Building
Sealed Combustion
2.12.4
When the Benchmark 1.5 Boiler is used to provide heat temporarily during ongoing building
construction, accumulated drywall dust, sawdust and similar particles can accumulate in the
unit’s combustion air intake filter and block combustion air flow. In these situations, AERCO
recommends that a disposable air intake filter be installed, temporarily, above the boiler
combustion air inlet.
AERCO recommends that the temporary air filter be cut from a McMaster-Carr part no.
2122K315 Polyester Air Filter Roll Tackfield, ½” thick, 16” wide, or equivalent. Cover the
Benchmark 1.5 air inlet with the blue side of the filter material facing outward to hold the dust on
Page 28 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Temporary Combustion Air Filtering During Construction
Page 29
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Benchmark 1.5LN Low NOx Boiler
Installation, Operation and Maintenance Manual
CHAPTER 2
INSTALLATION
the outside surface. Maximize the surface area of the filter covering the 8" diameter opening by
creating a dome out of the filter material.
Cover the flared duct opening with the blue side facing outward. During construction check the
filter for dust accumulation and replace it when the accumulation becomes noticeable.
2.13 BENCHMARK PUMP RELAY OPTION
An optional Benchmark pump relay allows the user to turn a pump on/off and open/close a
motorized valve as the boiler cycles on and off on demand. The Pump Delay Timer feature
allows the user to keep the pump running and keep the motorized valve open for up to 30
minutes after the boiler has shut down and the demand is satisfied.
The Benchmark pump relay (SPDT) contact is rated for:
• 10 A Resistive @ 277 VAC/28 VDC
• 1/3 HP N/O @ 120/240 VAC
• 1/6 HP N/C @ 120/240 VAC
• 480 VA Pilot Duty @ 240-277 VAC
If pump/valve load exceeds the above contact ratings, use a separate contact relay.
See Diagrams 2-11a and 2-11b.
To identify if the boiler is equipped with the BMK Pump Relay Option (part no. 69102), look for
the label and relay in the Power Box as shown in Figure 2-12.
Figure 2-11a: Schematic – System Pump Start using Boiler Pump Relay
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Benchmark 1.5LN Low NOx Boiler
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CHAPTER 2
INSTALLATION
Installation, Operation and Maintenance Manual
Figure 2-11b: Schematic – System Pump Start using a Separate Contact Relay
Figure 2-12: Identifying the Presence of BMK Pump Relay Option 69102
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Page 31
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CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
CHAPTER 3. CONTROL PANEL OPERATION
3.1 INTRODUCTION
The information in this Chapter provides a g uide to the operation of the Benchmark 1.5 Boiler
using the Control Panel mounted on the front of the unit. It is imperative that the initial startup of
this unit be performed by factory trained personnel. Oper ation prior to initial startup by factory
trained personnel will void the equipment warranty. In addition, the following WARNINGS and
CAUTIONS must be observed at all times.
NOTE
All of the installation procedures in Chapter 2 must be completed
before attempting to start the unit.
ELECTRICAL VOLTAGES IN THI S SYSTEM MAY INCLUDE 460,
208 AND 24 VOLTS AC. IT MUST BE SERVICED ONLY BY
FACTORY CERTIFIED SERVICE TECHNICIANS
WARNING
DO NOT ATTEMPT TO DRY FIRE THE BOILER. STARTING
THE UNIT WITHOUT A FULL WAT ER LEVEL CAN SERIOUSLY
DAMAGE THE UNIT AND MAY RESULT IN INJURY TO
PERSONNEL OR PROPERTY DA MAGE. THIS SITUATION WILL
VOID ANY WARRANTY.
3.2 CONTROL PANEL DESCRIPTION
The Benchmark 1.5 Control Panel shown in Figure 3-1 contains all of the controls, indicators
and displays necessary to operate, adjust and troubleshoot the Benchmark 1.5 Boiler. These
operating controls, indicators and displays are listed and described in Table 3-1. Additional
information on these items are provided in the individual operating procedures provided in this
Chapter.
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Benchmark 1.5LN Low NOx Boiler
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1
2
3
4
5
6
7
8
9
10
11
12
VALVE POSITION
CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Figure 3-1: Control Panel Front View
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NO.
DISPLAY
FUNCTION
8
CHAPTER 3
OPERATION
Table 3-1: Operating Controls, Indicators and Displays
Installation, Operation and Maintenance Manual
ITEM
CONTROL,
INDICATOR OR
1 LED Status Indicators
COMM
MANUAL
REMOTE
DEMAND
OUTLET
2
TEMPERATURE
Display
3 VFD Display
Four Status LEDs indicate the current operating status as
follows:
Lights when RS-232 communication is occurring
Lights when the unit is being controlled using the front panel
keypad.
Lights when the unit is being controlled by an external signal
from an Energy Management System
Lights when there is a demand for heat.
3–Digit, 7–Segment LED display continuously displays the
outlet water temperature. The °F or °C LED next to the
display lights to indicate whether the displayed temperature is
in degrees Fahrenheit or degrees Celsius. The °F or °C blinks
when operating in the Deadband Mode.
Vacuum Fluorescent Display (VFD) consists of 2 lines each
capable of displaying up to 16 alphanumeric characters. The
information displayed includes:
Startup Messages
Fault Messages
Operating Status Messages
Menu Selection
RS-232 Port
4
FAULT Indicator
5
CLEAR Key
6
READY Indicator
7
ON/OFF Switch
LOW WATER LEVEL
9
TEST/RESET
Switches
Port permits a Laptop Computer or External Modem to be
connected to the unit’s Control Panel.
Red FAULT LED indicator lights when a boiler alarm
condition occurs. An alarm message will appear in the VFD.
Turns off the FAULT indicator and clears the alarm message
if the alarm is no longer valid. Lockout type alarms will be
latched and cannot be cleared by simply pressing this key.
Troubleshooting may be required to clear these types of
alarms.
Lights ON/OFF switch is set to ON and all Pre-Purge
conditions have been satisfied.
Enables and disables boiler operation.
Allows operator to test operation of the water level monitor.
Pressing TEST opens the water level probe circuit and
simulates a Low Water Level alarm.
Pressing RESET resets the water level monitor circuit.
Pressing the CLEAR key (item 6) resets the display.
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Benchmark 1.5LN Low NOx Boiler
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NO.
DISPLAY
FUNCTION
Bargraph
CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Table 3-1: Operating Controls, Indicators and Displays (Continued)
ITEM
CONTROL,
INDICATOR OR
10 MENU Keypad
MENU
BACK
▲ (UP) Arrow
▼ (DOWN) Arrow
CHANGE
Consists of 6 keys which provide the following functions for
the Control Panel Menus:
Steps through the main menu categories shown in Figure 3-
2. The Menu categories wrap around in the order shown.
Allows you to go back to the previous menu level without
changing any information. Continuously pressing this key
will bring you back to the default status display in the VFD.
Also, this key allows you to go back to the top of a main
menu category.
When in one of the main menu categories (Figure 3-2),
pressing the ▲ arrow key will select the displayed menu
category. If the CHANGE key was pressed and the menu
item is flashing, pressing the ▲ arrow key will increment the
selected setting.
When in one of the main menu categories (Figure 3-2),
pressing this key will select the displayed menu category. If
the CHANGE key was pressed and the menu item is
flashing, pressing the ▼ arrow key will decrement the
selected setting.
Permits a setting to be changed (edited). When the
CHANGE key is pressed, the displayed menu item will begin
to flash. Pressing the ▲ or ▼ arrow key whe n the item is
flashing will increment or decrement the displayed setting.
ENTER
11
12
AUTO/MAN Switch
VALVE POSITION
Saves the modified menu settings in memory. The display
will stop flashing.
This switch toggles the boiler between the Automatic and
Manual modes of operation. When in the Manual (MAN)
mode, the front panel controls are enabled and the
MANUAL status LED lights.
When in the Automatic (AUTO) mode, the MANUAL status
LED will be off and the front panel controls disabled.
20 segment red LED bargraph continuously shows the
Air/Fuel Valve position in 5% increments from 0 to 100%
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Page 35
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CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
3.3 CONTROL PANEL MENUS
The Control Panel incorporates an extensive menu structure which permits the operator to set
up, and configure the unit. The menu structure consists of five major menu categories which are
applicable to this manual. These categories are shown in Figure 3-2. Each of the menus
shown, contain options which permit operating parameters to be viewed or changed. The
menus are protected by a password levels to prevent unauthorized use.
Prior to entering the correct password, the options contained in the Operation, Setup,
Configuration and Tuning Menu categories can be viewed. However, with the exception of
Internal Setpoint Temperature (Configuration Menu), none of the viewable menu options can be
changed.
Once the valid level 1 password (159) is entered, the opt ions listed in the Setup. Configuration
and Tuning Menus can be viewed and changed, if desired. The Combustion Cal Menu is
protected by the level 2 password which is used in Chapter 4 to perform combustion calibration
prior to service use.
3.3.1
Accessing and initiating each menu and option is accomplished using the Menu Keys shown in
Figure 3-1. Therefore, it is imperative that you be thoroughly familiar with the following basic
steps before attempting to perform specific menu procedures.
Menu Processing Procedure
The Control Panel will normally be in the Operating Menu and the VFD will display the 1.
current unit status. Pressing the ▲ or ▼ arrow key will display the other available data
items in the Operating Menu.
Press the MENU key. The display will show the Setup Menu, which is the next menu 2.
category shown in Figure 3-2. This menu contains the Password option which must be
entered if other menu options will be changed.
Continue pressing the MENU key until the desired menu is displayed. 3.
With the desired menu displayed, press the ▲ or ▼ arrow key. The first option in the 4.
selected menu will be displayed.
Continue to press the ▲ or ▼ arrow key until the desired menu option is displayed. 5.
Pressing the ▲ arrow key will display the available menu options in the Top-Down
sequence. Pressing the ▼ arrow key will display the options in the Bottom-Up
sequence. The menu options will wrap-around after the first or last available option is
reached.
To change the value or setting of a displayed menu option, press the CHANGE key. The 6.
displayed option will begin to flash. Press the ▲ or ▼ arrow key to scroll through the
available menu option choices for the option to be changed. The menu option choices
do not wrap around.
To select and store a changed menu item, press the ENTER key. 7.
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OPERATING
SETUP
CONFIGURATION
TUNING
COMBUSTION CAL
CALIBRATION
(NOT USED IN THIS O & M)
LEVEL 2 PWD
LEVEL 1 PWD
DIAGNOSTICS
(NOT USED IN THIS O & M)
CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Figure 3-2: Control Panel Menu Structure
The following paragraphs provide brief descriptions of the options
contained in each menu. Refer to Appendix A for detailed descriptions of
each menu option. Refer to Appendix B for listings and descriptions of
displayed startup, status and error messages.
3.4 OPERATING MENU
The Operating Menu displays a number of key operating parameters for the unit as listed in
Table 3-2. This menu is “Read-Only” and does not allow personnel to change or adjust any
displayed items. Since this menu is “Read-Only”, it can be viewed at any time without entering a
password. Pressing the ▲ arrow key to display the menu items in the order listed (Top-Down).
Pressing the ▼ arrow key will display the menu items in reverse order (Bottom-Up).
NOTE
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CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
NOTE
The Outdoor Temp display item shown with an asterisk in T able 3-2 will not
be displayed unless the Outdoor Sensor function has been enabled in the
Configuration Menu (Table 3-4).
Table 3-2: Operating Menu
Available Choices or Limits
Menu Item Display Minimum Maximum Default
Status Message
Active Setpoint 40°F 240°F
AIR Temp -70°F 245°F
Outdoor Temp* -70°F 130°F
Valve Position In 0% 100% Valve Position
Flame Strength 0% 100%
Run Cycles 0 999,999,999
Run Hours 0 999,999,999
Fault Log 0 19 0
3.5 SETUP MENU
The Setup Menu (Table 3-3) permits the operator to enter the unit password (159) which is
required to change the menu options. To prevent unauthorized use, the password will time-out
after 1 hour. Therefore, the correct password must be reenter ed when required. In addition to
permitting password entries, the Setup Menu is also used to enter date and time, units of
temperature measurements and entries required for external communication and control of the
unit via the RS-232 port. A view-only software version display is also provided to indicate the
current Control Box software version.
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Benchmark 1.5LN Low NOx Boiler
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CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Table 3-3. Setup Menu
Available Choices or Limits
Menu Item Display Minimum Maximum Default
Passsword
Language
Time
Date
Unit of Temp
Comm Address
Baud Rate
Min. Upload Timer
Unit Alpha
Unit Year
Unit Serial #
Software
0 9999 0
English English
12:00 am 11:59 pm
01/01/00 12/31/99
Fahrenheit or Celsius Fahrenheit
0 127 0
2400, 4800, 9600, 19.2K 9600
30 9999 0
A Z E
00 99 00
0000 9999 0000
Ver. 0.0 Ver. 9.9 Current
3.6 CONFIGURATION MENU
The Configuration Menu shown in Table 3-4 permits adjustment of the Internal Setpoint (Setpt)
temperature regardless of whether the valid password has been entered. Setpt is required for
operation in the Constant Setpoint mode. The remaining options in this menu require the valid
password to be entered, prior to changing existing entries. This menu contains a number of
other configuration settings which may or may not be displayed, depending on the current
operating mode setting.
NOTE
The Configuration Menu settings shown in Table 3-4 are Factory-Set in
accordance with the requirements specified for each individual order.
Therefore, under normal operating conditions, no changes will be required.
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Page 39
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
Available Choices or Limits
Menu Item Display
Minimum
Maximum
Default
of Table 3-4)
Reset)
= Enabled)
Aux Start On Dly
0 sec.
120 sec.
0 sec.
CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Table 3-4. Configuration Menu
Internal Setpt
Lo Temp
Hi Temp Limit 130°F
Limit
Unit Type
KC Boiler, KC Boiler LN,
BMK Boiler Std, BMK Boiler
BMK Boiler
LN
LN, BMK Boiler Dual, KC
Water Heater , KC Water
Heater LN, Innovation WH
Unit Size
(See NOTE at end
750 MBH, 1000 MBH, 1500
MBH, 2000 MBTU, 3000
1500 MBH
(1.5 MBTU)
MBH, 6000 MBH
Fuel Type Natural Gas, Propane Natural Gas
Boiler Mode
Constant Setpoint,
Remote Setpoint,
Constant
Setpoint
Direct Drive
Combination
Outdoor Reset
Remote Signal
(If Mode = Remote
Setpoint, Direct
Drive or
4 – 20 mA/1 – 5V
0 -20 mA/0 – 5V
PWM Input (BMS)
Network
4 – 20 mA,
1-5V
Combination)
Bldg Ref Temp
40°F 230°F 70°F
(If Mode = Outdoor
Reset Ratio
0.1 9.9 1.2
(If Mode = Outdoor
Reset)
Outdoor Sensor Enabled or Disabled Disabled
System Start Tmp
30°F 100°F 60°F
(If Outdoor Sensor
Setpt Lo Limit 40°F Setpt Hi Limit 60°F
Setpt Hi Limit Setpt Lo Limit 195°F 195°F
Temp Hi Limit 40°F 210°F 195°F
Max Valve Position 40% 100% 100%
Pump Delay Timer 0 min. 30 min. 0 min.
Pump Delay Timer 0 min. 30 min. 0 min.
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Benchmark 1.5LN Low NOx Boiler
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Available Choices or Limits
Menu Item Display
Minimum
Maximum
Default
CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Table 3-4. Configuration Menu - Continued
Failsafe Mode Shutdown or Constant Setpt Shutdown
*Analog Output
(See CAUTION at
end of Table 3-4 )
Off, Setpoint, Outlet Temp,
Valve Position 4-20 mA,
Valve Position 0-10V
*Valve
Position
0-10V
Low Fire Timer 2 sec. 600 sec. 2 sec.
Setpt Limiting Enabled or Disabled Disabled
Setpt Limit Band 0°F 10°F 5°F
Network Timeout 5 Sec 999 Sec 30 Sec
HI DB Setpt EN 0% 100% 30%
Demand Offsert 0 25 10
Deadband High 0 25 2
Deadband Low 0 25 2
Spark Monitor Enabled or Disabled Disabled
Spark Current Display
NOTE
Only the Unit Sizes applicable to the selected Unit Type will be displayed.
DO NOT CHANGE the Analog Output Menu Item from its Default setting
(Valve Position 0-10V).
3.7 TUNING MENU
The Tuning Menu items in Table 3-5 are Factory set for each individual unit. Do not change
these menu entries unless specifically requested to do so by Factory-Trained personnel.
3.8 COMBUSTION CAL MENU
The Combustion Cal (Calibration) Menu items in Table 3-6 are used to vary the speed of the
unit’s blower motor based on air temperature and air density at prescribed Air/Fuel Valve
positions (% open). This is accomplished by providing a DC drive voltage to t he motor which
adjusts the rotational speed of the blower to maximize combustion efficiency and ensure the unit
conforms to the Nitrogen Oxide (NOx) and Carbon Monoxide (CO) emissions specified in
Chapter 4. The valve positions (%) and default drive voltages are listed in Table 3-6.
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*CAUTION!
Page 41
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
Limits
Menu Item Display
Minimum
Maximum
Default
Available Choices or Limits
Menu Item Display
Minimum
Maximum
Default
CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Table 3-5: Tuning Menu
Available Choices or
Prop Band 1°F 120°F 70°F
Integral Gain 0.00 2.00 1.00
Derivative Time
0.00 min 2.00 min 0.00 min
(if Unit Type = Boiler
Warmup Prop Band Range = 1 - 120 95
Warmup Int Gain Range = 1 - 200 50
Warmup PID Timer Range = 1 - 240 20
Reset Defaults Yes, No, Ar e You Sure No
Table 3-6: Combustion Cal Menu
CAL Voltage 16% .25 8.20 1.80v
CAL Voltage 30% .25 8.20 3.20v
CAL Voltage 45% .25 8.20 3.70v
CAL Voltage 60% .25 8.20 3.80
CAL Voltage 80% .25 8.20 4.60
CAL Voltage 100% .25 8.20 6.00
SET Valve Position 0% 100% 0%
Blower Output Mon itor Bl o wer Output Vo lt age .00
3.9 START SEQUENCE
When the Control Box ON/OFF switch is set to the O N position, it checks all pre-purge safety
switches to ensure they are closed. These switches include:
• Safety Shut-Off Valve Proof of Closure (POC) switch
• Low Water Level switch
• High Water Temperature switch
• High Gas Pressure switch
• Low Gas Pressure switch
• Blower Proof switch
• Blocked Inlet switch
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Benchmark 1.5LN Low NOx Boiler
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SSOV
MANUAL GAS
CHAPTER 3
OPERATION
If all of the above switches are closed, the READY light above the ON/OFF switch will light and
the unit will be in the Standby mode.
When there is a demand for heat, the following events will occur:
If any of the Pre-Purge safety device switches are open, the appropriate
fault message will be displayed. Also, the appropriate fault messages will
be displayed throughout the start sequence, if the required conditions are
not observed.
The DEMAND LED stat us indic a tor will light. 1.
The unit checks to ensure that the Proof of Closure (POC) switch in the downstream 2.
Safety Shut-Off Valve (SSOV) is closed. See Figure 3-3 for SSOV location.
With all required safety device switches closed, a purge cycle will be initiated and the 3.
following events will occur:
Installation, Operation and Maintenance Manual
NOTE
a. The Blower relay energizes and turns on blower.
b. The Air/Fuel Valve rotates to the full-open purge position and closes purge position
switch. The dial on the Air/Fuel Valve (Figure 3-4) will read 100 to indicate that it is
full-open (100%).
c. The VALVE POSITION bargraph will show 100%.
SHUT-OFF
VALVE
TO
AIR/FUEL
VALVE
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GAS
INLET
Figure 3-3: SSOV Location
Page 43
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
100
DETAIL “A”
TO BLOWER
AIR IN
DIAL
(DETAIL “A”)
STEPPER
MOTOR
CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Next, the blower proof switch on the Air/Fuel Valve (Figure 3-5) closes. The display will 4.
show Purging and indicate the elapsed time of the purge cycle in seconds.
Upon completion of the purge cycle, the Control Box initiates an ignition cycle and the 5.
following events occur:
a. The Air/Fuel Valve rotates to the low-fire ignition position and closes the ignition
switch. The dial on the Air/Fuel Valve (Figure 3-6) will read between 25 and 35 to
indicate that the valve is in the low-fire position.
b. The igniter relay is activated and provides ignition spark.
c. The gas Safety Shut-Off Valve (SSOV) is energized (opened) allowing gas to flow
into the Air/Fuel Valve.
Figure 3-4: Air/Fuel Valve In Purge Position
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Page 44
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
AIR/FUEL
VALVE OUTLET
TO BLOWER
BLOWER
PROOF
SWITCH
25
TO BLOWER
AIR IN
DIAL
(DETAIL “A”)
STEPPER
MOTOR
DETAIL “A”
CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
Figure 3-5: Blower Proof Switch
Up to 7 seconds will be allowed for ignition to be detected. The igniter relay will be 6.
turned off one second after flame is detected.
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Figure 3-6: Air/Fuel Valve In Ignition Position
Page 45
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
Position (% Open)
(BTU/Hr)
(% of Full Capacity)
0% 0 0
10% 0 0
16%
(Stop Level)
75,000
5.0%
20%
157,000
10%
30%
310,000
21%
40%
534,000
36%
50%
783,000
52%
60%
970,000
65%
70%
1,140,000
76%
80%
1,240,000
83%
90%
1,370,000
91%
100%
1,500,000
100%
CHAPTER 3
OPERATION
After 2 seconds of continuous flame, Flame Proven will be displayed and the flame 7.
strength will be indicated. After 5 seconds, the current date and time will be displayed in
place of the flame strength.
With the unit firing properly, it will be controlled by the temperature controller circuitry. 8.
The boiler’s VALVE POSITION will be continuously displayed on the front panel
bargraph.
Once the demand for heat has been satisfied, the Control Box will turn off the dual SSOV gas
valves. The blower relay will be deactivated and the Air/Fuel Valve will be closed. Standby will
be displayed.
Installation, Operation and Maintenance Manual
3.10 START/STOP LEVELS
The start and stop levels are the Air/Fuel Valve positions (% open) that start and stop the unit,
based on load. These levels are Factory preset as follows:
Start Level: 20%
Stop Level: 16%
Normally, these settings should not require adjustment.
Note that the energy input of the boiler is not linearly related to the Air/Fuel Valve position. Refer
to Table 3-7 for the relationship between the energy input and Air/Fuel Valve position for a unit
running on natural gas.
Table 3-7: Relationship Between Air/Fuel Valve Position and Energy Input For Unit
Running on Natural Gas
Air/Fuel Valve
Energy Input
Boiler Energy Input
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Benchmark 1.5LN Low NOx Boiler
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CHAPTER 3
OPERATION
Installation, Operation and Maintenance Manual
(This Page Is Intentionally Blank)
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Page 47
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
CHAPTER 4
INITIAL START-UP
Installation, Operation and Maintenance Manual
CHAPTER 4. INITIAL START-UP
4.1 INI TIAL START-UP REQUIREMENTS
The requirements for the initial start-up of the Benchmark 1.5 Boiler consists of the following:
• Complete installation (Chapter 2)
• Set proper controls and limits (Chapter 3)
• Perform combustion calibration (Chapter 4)
• Set up mode of operation (Chapter 5)
• Test safety devices (see Chapter 6)
All applicable Installation procedures in Chapter 2 must be fully completed before performing
initial start-up. The initial start-up must be successfully completed prior to putting the unit into
service. Starting a unit without the proper piping, venting, or electrical systems can be
dangerous and may void the product warranty. The following start-up instructions should be
followed precisely in order to operate the unit safely and at a high thermal eff iciency, with low
flue gas emissions.
Initial unit start-up is to be performed ONLY by AERCO factory trained start-up and service
personnel. After performing the start-up procedures in this Chapter, it will be necessary to
perform the Mode of Operation settings in Chapter 5, and the Safety Device Testing procedures
in Chapter 6 to complete all initial start-up requirements.
AERCO Gas Fired Startup Sheets, included with each Benchmark Boiler, must be completed for
each unit for warranty validation. A copy of these sheets must be returned promptly to AERCO
at:
AERCO International, Inc.
159 Paris Ave.
Northvale, NJ 07647
WARNING
DO NOT ATTEMPT TO DRY FIRE THE BOILER.
STARTING THE UNIT WITHOUT A FULL WATER LEVEL
CAN SERIOUSLY DAMAGE THE UNIT AND MAY RESULT
IN INJURY TO PERSONNEL OR PROPERTY DAMAGE.
THIS SITUATION WILL VOID ANY WARRANTY.
All applicable installation procedures in Chapter 2 must be
completed before attempting to start the unit.
4.2 TOOLS AND INSTRUMENTATION FOR COMBUSTION CALIBRATION
To properly perform combustion calibration, the proper instruments and tools must be used and
correctly attached to the unit. The following paragraphs outline the necessary tools and
instrumentation as well as their installation.
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Page 48
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
TO
SSO
OFF VALVE
1/4” NPT PLUG
TEST/CALIBRATION)
RSI
1/4” NPT PLUG
CHAPTER 4
INITIAL START-UP
4.2.1 Tools & Instrumentation
The following tools and instrumentation are necessary to perform combustion calibration of the
unit:
• Digital Combustion Analyzer: Oxygen accuracy to ± 0.4%; Carbon Monoxide (CO) and
Nitrogen Oxide (NOx) resolution to 1PPM.
• 16 inch W.C. manometer or equivalent gauge and plastic tubing.
• 1/4" NPT-to-barbed fittings for use with gas supply manometer or gauge.
• Small and large flat blade screwdrivers.
• Tube of silicone adhesive
Installation, Operation and Maintenance Manual
4.2.2
Installing Gas Supply Manometer
The gas supply manometer (or gauge) is used to calibrate the gas pressure to be monitored on
the downstream side of the SSOV during the Combustion Calibration procedures described in
paragraph 4.4.
The gas supply manometer is installed at the downstream location on the 1/4” NPT port shown
in Figure 4-1. Note that a 1/4” plug must be removed from the port in order to install the
manometer.
MANUAL SHUTOFF VALVE
(INSTALL
MONOMETER HERE
FOR COMBUSTION
CALIBRATION)
AIR/FUEL
VALVE
RSI
SOLENOID
VALVE
(INSTALL
MONOMETER HERE
FOR RSI PRESSURE
PRESSURE
REGULATOR
Figure 4-1: Combustion Calibration & RSI Manometer Installation Locations
Page 48 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
RSI GAS
VALVE
RSI BLEED-
GAS INLET
Page 49
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
EXHAUST
MANIFOLD
CONDENSATE DRAIN
CONNECTION
VENT PROBE
PORT
UNIT
FRAME
PARTIAL TOP VIEW
CHAPTER 4
INITIAL START-UP
Install the 16” W.C. manometer(s) as described in the following steps:
Turn off the main gas supply upstream of the unit. 1.
Remove the top panel and left or right side panel from the boiler to access the gas train 2.
components.
Perform the RSI reg ulator Safe Test as described in paragraph 4.3. If test shows a 3.
successful RSI ignition, proceed to the next step. If RSI ignition is not successful, follow
instructions in paragraph 4.3 before attempting Combustion Calibration.
To monitor the gas pressure on the downstream side of the SSOV during Combustion 4.
Calibration (paragraph 4.4), remove the 1/4” NPT plug from the leak detection ball valve
on the downstream side of the SSOV as shown in Figure 4-1.
Install a NPT-to-barbed fitting into the tapped plug port. 5.
Attach one end of the plastic tubing to the barbed fitting and the other end to the 16” 6.
W.C. manometer.
Installation, Operation and Maintenance Manual
4.1.1
The unit contains a NPT plug on the exhaust manifold at the rear of the unit as shown in Figure
4-2. Prepare the port for the combustion analyzer probe as follows:
Remove the plug from the probe port on the top of the exhaust manifold. 1.
If necessary, adjust the stop on the combustion analyzer probe so that it will extend mid-2.
Accessing the Vent Probe Port
way into the flue gas flow. DO NOT install the probe at this time.
Figure 4.2: Analyzer Probe Hole Location
4.3 RSI REGULATOR SAFE TEST
The Benchmark 1.5LN contains a RSI regulator in the Regulated Staged Ignition (RSI) line of
the unit. The RSI regulator is calibrated prior t o shipment, however the RSI system should be
safe tested prior to performing the Combustion Calibration Procedure to ensure it is working
properly. RSI regulator safe testing is performed as follows:
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Page 50
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
CHAPTER 4
INITIAL START-UP
Close the main gas supply shut-off valve upstream of the unit. 1.
Refer to Figure 4.1 and CLOSE the following valves in the unit’s gas train: 2.
• RSI gas valve
• RSI Bleed-off Valve
• Manual shut-off valve to Air/Fuel Valve.
OPEN the main gas supply upstream of the unit. 3.
Turn ON electrical power to the system. 4.
Slowly OPEN the RSI Gas Valve. 5.
Turn on the external gas supply to the unit. 6.
Slowly open the RSI gas supply valve. 7.
Start the boiler in MANUAL Mode. 8.
Look into the observation port in the top head (see Figure 4-3) and ensure that you 9.
observe the orange glow of the RSI flame during the ignition trial period.
Installation, Operation and Maintenance Manual
Conduct at least three safe RSI ignitions while looking into the observation port in the top 10.
head. Assure the igniter lights immediately with a strong orange flame after the Staged
Ignition Solenoid Valve opens, and then proceed with the Combustion Calibration
procedure described in Section 4.4.
NOTE
Clear any Flame Loss During Ignition messages during the tests by
pressing The CLEAR key on control panel.
IMPORTANT!
If you do NOT see the orange glow from the RSI ignition in the observation
port, refer to Paragraph 7.4.1.2 to calibrate the RSI regulator. Do NOT
proceed with Combustion Calibration until the RSI is igniting properly.
Figure 4-3: Observation Port Location
Page 50 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Page 51
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
BRASS HEX
HEAD CAP
(REMOVE TO
ACCESS GAS
PRESSURE
ADJUSTMENT
SCREW)
SSOV ACTUATOR
CHAPTER 4
INITIAL START-UP
Installation, Operation and Maintenance Manual
4.4 NATURAL GAS COMBUSTION CALIBRAT ION
The Benchmark 1.5LN Boiler is combustion calibrated at the factory prior to shipping. However,
recalibration as part of initial start-up is necessary due to changes in the local altitude, g as BTU
content, gas supply piping and supply regulators. Factory Test Data sheets are shipped with
each unit. These sheets must be filled out and returned to AERCO for proper Warranty
Validation.
It is important to perform the following procedure as outlined. This will keep readjustments to a
minimum and provide optimum performance.
Open the water supply and return valves to the unit and ensure that the system pumps 1.
are running.
Open the natural gas supply valve(s) to the unit. 2.
Set the control panel ON/OFF switch to the OFF position. 3.
Turn on external AC power to the unit. The display will show LOSS OF POWER and the 4.
time and date.
Set the unit to the Manual Mode by pressing the AUTO/MAN key. A flashing Manual 5.
Valve Position message will be displayed with the present rate in %. Also, the MANUAL
LED will light.
Adjust the air/fuel valve position to 0% by pressing the ▼ arrow key. 6.
Ensure that the leak detection ball valve down-stream of the SSOV is open. 7.
Set the ON/OFF switch to the ON position. 8.
Change the valve position to 29% using the ▲ arrow key. The unit should begin its start 9.
sequence and fire.
Next, verify that the gas pressure downstream of the SSOV is 3” W.C. for both FM and 10.
IRI gas trains. If gas pressure adjustment is required, remove the brass hex nut on the
downstream SSOV actuator (IRI gas train) to access the gas pressure adjustment screw
(Figure 4-4). Make gas pressure adjustments using a flat-tip screwdriver to obtain 3”
W.C.
Figure 4-4: Gas Pressure Adjustment Screw Location
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Page 52
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
Inlet Air
Oxygen
± 0.2
Carbon
e
>100°F
4.8 %
<100 ppm
<30 ppm
90°F
5.0 %
<100 ppm
<30 ppm
80°F
5.2 %
<100 ppm
<30 ppm
<70°F
5.3 %
<100 ppm
<30 ppm
USE 1/2"
WRENCH TO
INCREASE (CW)
OR DECREASE
(CCW) INLET AIR
IRIS
ADJUSTMENT
VIEW A - A
AIR INLET
IRIS AIR
DAMPER
FRONT
A
A
AIR/FUEL
VALVE
CHAPTER 4
INITIAL START-UP
Increase the valve open position to 100% and verify that the gas pressure downstream 11.
of the SSOV remains at 3” W.C. Readjust pressure if necessary.
With the valve position at 100%, insert the combustion analyzer probe into the flue probe 12.
opening and allow enough time for the combustion analyzer to settle.
Compare the measured oxygen level to the oxygen range for the inlet air temperature 13.
shown in Table 4-1. Also, ensure that the carbon monoxide (CO) and nitrogen oxide
(NOx) readings do not exceed the values shown.
Installation, Operation and Maintenance Manual
Table 4-1: Combustion Oxygen Levels for a 100% Air/Fuel Valve Position
Temp
If necessary, adjust the iris air damper shown in Figure 4-5 until the oxygen level is 14.
within the range specified in Table 4-1.
Once the oxygen level is within the specified range at 100%, lower the valve position to 15.
80%.
%
Monoxid
NOx
Page 52 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Figure 4-5: Iris Air Damper Location/Adjustment
Page 53
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
Oxygen
± 0.2
Carbon
6.0 %
<100 ppm
<30 ppm
CHAPTER 4
INITIAL START-UP
The remaining combustion calibration steps are performed using the
Combustion Cal Menu included in the C-More Control System. The
combustion calibration control functions will be used to adjust the oxygen
level (%) at air/fuel valve positions of 80%, 60%, 45%, 30% and 16% as
described in the following steps. These steps assume that the inlet air
temperature is within the range of 50°F to 100°F.
Press the MENU key on the front panel of the C-MORE and access the Setup menu. 16.
Enter password 6817 and then press the ENTER key.
Press the MENU key on the front panel of the C-MORE until Combustion Cal Menu 17.
appears on the C-More display.
Press the ▲ arrow key until SET Valve Position appears on the C-MORE display. 18.
Press the CHANGE key. SET Valve Position will begin to flash. 19.
Press the ▲ arrow key until the SET Valve Position reads 80%. Press the ENTER key. 20.
Installation, Operation and Maintenance Manual
NOTE
Next, press the down (▼) arrow key until CAL Voltage 80% is displayed. 21.
Press the CHANGE key and observe that CAL Voltage 80% is flashing. 22.
The oxygen level at the 80% valve position should be as shown below. Also, ensure that 23.
the carbon monoxide (CO) and nitrogen oxide (NOx) readings do not exceed the values
shown.
Table 4-2: Combustion Oxygen Levels for a 80% Air/Fuel Valve Position
%
If the oxygen level is not within the specified range, adjust the level using the ▲ and ▼ 24.
arrow keys. This will adjust the output voltage to the blower motor as indicated on the
display. Pressing the ▲ arrow key increases the oxygen level and pressing the down ▼
arrow key decreases the oxygen level.
Once the oxygen level is within the specified range at 80%, press the ENTER key to 25.
store the selected blower output voltage for the 80% valve position.
The remaining steps basically repeat the procedures in steps 18 through
25 for valve positions of 60%, 45%, 30% and 16%. However, since oxygen
levels vary, these steps are repeated in their entirety. When performing
these steps, also ensure that the carbon monoxide (CO) and nitrogen oxide
(NOx) readings do not exceed the values shown for each valve position.
Monoxide NOx
NOTE
Press the ▲ arrow key until SET Valve Position appears on the C-MORE display. 26.
Press the CHANGE key. SET Valve Position will begin to flash. 27.
Press the ▼ arrow key until the SET Valve Position reads 60% and press the ENTER 28.
key.
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Page 54
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
Oxygen
± 0.2
Carbon
6.3 %
<50 ppm
<30 ppm
Oxygen
± 0.2
Carbon
7.0 %
<50 ppm
<30 ppm
CHAPTER 4
INITIAL START-UP
Press the down ▼ arrow key until CAL Voltage 60% is displayed. 29.
Press the CHANGE key. CAL Voltage 60% will begin to flash. 30.
The oxygen level at the 60% valve position should be as shown below. Also, ensure that 31.
the carbon monoxide (CO) and nitrogen oxide (NOx) readings do not exceed the values
shown.
Table 4-3: Combustion Oxygen Levels for a 60% Air/Fuel Valve Position
Installation, Operation and Maintenance Manual
%
If the oxygen level is not within the specified range, adjust the level using the ▲ and ▼ 32.
arrow keys. This will adjust the output voltage to the blower motor as indicated on the
display. Pressing the ▲ arrow key increases the oxygen level and pressing the ▼ arrow
key decreases the oxygen level.
Once the oxygen level is within the specified range at 60%, press the ENTER key to 33.
store the selected blower output voltage for the 60% valve position.
Press the ▲ arrow key until SET Valve Position appears on the C-MORE display. 34.
Press the CHANGE key. SET Valve Position will begin to flash. 35.
Press the ▼ arrow key until the SET Valve Position reads 45%, then press the ENTER 36.
key.
Press the ▼ arrow key until CAL Voltage 45% is displayed. 37.
Press the CHANGE key. CAL Voltage 45% will begin to flash. 38.
The oxygen level at the 45% valve position should be as shown below. Also, ensure that 39.
the carbon monoxide (CO) and nitrogen oxide (NOx) readings do not exceed the values
shown.
Monoxide NOx
Table 4-4: Combustion Oxygen Levels for a 45% Air/Fuel Valve Position
If the oxygen level is not within the specified range, adjust the level using the ▲ and ▼ 40.
arrow keys. This will adjust the output voltage to the blower motor as indicated on the
display. Pressing the ▲ arrow key increases the oxygen level and pressing the ▼ arrow
key decreases the oxygen level.
Once the oxygen level is within the specified range at 45%, press the ENTER key to 41.
store the selected blower output voltage for the 45% valve position.
Press the ▲ arrow key until SET Valve Position appears on the C-MORE display. 42.
Press the CHANGE key. SET Valve Position will begin to flash. 43.
Press the ▼ arrow key until the SET Valve Position reads 30%, then press the ENTER 44.
key.
Press the ▼ arrow key until CAL Voltage 30% is displayed. 45.
Press the CHANGE key. CAL Voltage 30% will begin to flash. 46.
Page 54 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
%
Monoxide
NOx
Page 55
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
Oxygen
± 0.2
Carbon
7.0 %
<50 ppm
<30 ppm
Oxygen
± 0.2
Carbon
8.0 %
<50 ppm
<30 ppm
CHAPTER 4
INITIAL START-UP
The oxygen level at the 30% valve position should be as shown below. Al s o, ens ure that 47.
the carbon monoxide (CO) and nitrogen oxide (NOx) readings do not exceed the values
shown.
Installation, Operation and Maintenance Manual
Table 4-5: Combustion Oxygen Levels for a 30% Air/Fuel Valve Position
%
If the oxygen level is not within the specified range, adjust the level using the ▲ and ▼ 48.
arrow keys. This will adjust the output voltage to the blower motor as indicated on the
display. Pressing the ▲ arrow key increases the oxygen level and pressing the ▼ arrow
key decreases the oxygen level.
Once the oxygen level is within the specified range at 30%, press the ENTER key to 49.
store the selected blower output voltage for the 30% valve position.
Press the ▲ arrow key until SET Valve Position appears on the C-MORE display. 50.
Press the CHANGE key. SET Valve Position will begin to flash. 51.
Press the ▼ arrow key until the SET Valve Position reads 16%, then press the ENTER 52.
key.
Press the ▼ arrow key until CAL Voltage 16% is displayed. 53.
Press the CHANGE key. CAL Voltage 16% will begin to flash. 54.
The oxygen level at the 16% valve position should be as shown below. Also, ensure that 55.
the carbon monoxide (CO) and nitrogen oxide (NOx) readings do not exceed the values
shown.
Monoxide NOx
Table 4-6: Combustion Oxygen Levels for a 16% Air/Fuel Valve Position
If the oxygen level is not within the specified range, adjust the level using the ▲ and ▼ 56.
arrow keys. This will adjust the output voltage to the blower motor as indicated on the
display. Pressing the ▲ arrow key increases the oxygen level and pressing the ▼ arrow
key decreases the oxygen level.
Once the oxygen level is within the specified range at 16%, press the ENTER key to 57.
store the selected blower output voltage for the 16% valve position.
This completes the natural gas combustion calibration procedure. 58.
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%
Monoxide NOx
Page 56
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
CHAPTER 4
INITIAL START-UP
Installation, Operation and Maintenance Manual
4.5 UNIT REASSEMBLY
Once the combustion calibration adjustments are properly set, the unit can be reassembled for
service operation.
Set the ON/OFF switch in the OFF position. 1.
Disconnect AC power from the unit. 2.
Shut off the gas supply to the unit. 3.
Remove the manometer and barbed fittings and reinstall the NPT plug using a suitable 4.
pipe thread compound.
Remove the combustion analyzer probe from the vent hole. Replace the NPT plug in the 5.
vent hole using a suitable pipe joint compound.
Replace the unit’s side panels and front door. 6.
4.6 OVER-TEMPERATURE LIMIT SWITCHES
The unit contains three (3) types of over-temperature limit switches. These switches consist of a
manual reset switch, a rotary dial adjustable switch and a digital alarm switch. These switches
are mounted on a plate as shown in Figure 4-6. The switches can be accessed by opening the
front panel door of the unit.
The manual reset switch is not adjustable and is permanently fixed at 210°F. This switch will
shut down and lock out the boiler if the water temperature exceeds 210°F. Following an overtemperature condition, it must be manually reset by pressing the manual reset button shown in
Figurer 4-6 before the boiler can be restarted.
The rotary dial over-temperature switch is manually adjustable fr om xxx to yyy ºF. This switch
allows the boiler to restart, once the temperature drops below the selected temperatur e setti ng
on the dial. Set the dial on this over-temperature switch to the desired setting.
The digital alarm switch shown in Figures 4-6 and 4-7 is preset at the factory to 210ºF and
should not be changed. If an over-temperature condition is detected, this switch autom atically
shuts down the boiler and sounds an audible alarm. If desired, the over-temperature alarm
switch settings can be checked or adjusted using the procedure in paragraph 4.6.1.
Page 56 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Page 57
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
FRONT VIEW
ADJUSTABLE
TEMPERATURE
LIMIT SWITCH
RESET BUTTON
FOR MANUAL
TEMPERATURE
LIMIT SWITCH
SEE
DETAIL “A”
DETAIL “A”
F
Alarm
DIGITAL OVER-
TEMPERATURE
ALARM SWITCH
CHAPTER 4
INITIAL START-UP
Installation, Operation and Maintenance Manual
Figure 4-6: Over Temperature Limit Switch Locations
4.6.1
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Digital Alarm Switch Ch ecks and Adjustments
Page 58
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
F
Alarm
RST
SET
Limit Control
CHAPTER 4
INITIAL START-UP
Installation, Operation and Maintenance Manual
The digital alarm switch settings can be checked or adjusted using the controls and display on
the front panel of the switch illustrated and described in Figure 4-7 and Table 4-7..
Figure 4-7: Digital Alarm Switch Front Panel
Table 4-6: Digital Alarm Switch Controls and Display
CONTROL or
Display
LED Display TEMP status
MEANING
Displays current water temperature or
setpoint.
RST RESET Button Resets the unit after an alarm condition.
UP Button Increases the displayed temperature.
DOWN Button Decreases the displayed temperature.
SET SET Button
Used to access and store parameters in the
unit.
FUNCTION
Perform the following steps to check or adjust the digital alarm switch settings:
1. Set the ON/OFF to the ON position.
2. Press the SET button on the Digital Alarm Switch. SP will appear in the display.
3. Press the SET button again. The current over-temperatur e limit value stored in memory will
be displayed. (default = 210°F).
4. If the display does not show the required over-temperature alarm setting, press the ▲ or ▼
arrow button to change the display to the desired temperature setting.
Page 58 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Page 59
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
CHAPTER 4
INITIAL START-UP
5. Once the desired over-temper ature al arm setting (210ºF) is displayed, press the SET button
to store the setting in memor y .
6. To calibrate the offset (P1), press and hold the SET button for 8 seconds on the Digital
Alarm Switch. Access code value 0 should appear in the display. The switch comes fr om the
factory with the code set at 0. AERCO recommends that you do not change this code.
7. Press the SET button again to enter the code. The first parameter label (SP) will appear in
the display.
8. Using the ▲ and ▼ arrow keys, select parameter P1.
9. Press SET to view the value stored in memory.
10. If the desired value is not displayed, modify the setting using the ▲ and ▼ arrow keys. The
value can be changed from -10° to +10° offset. Press SET to enter the value and exit to the
text parameter.
11. To exit the programming mode, press the SET and ▼ buttons simultaneously, or simply wait
one minute and the display will automatically exit the programming mode.
Installation, Operation and Maintenance Manual
12. Once the programming mode has been exited, the display will show the current outlet water
temperature of the boiler.
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Page 60
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CHAPTER 4
INITIAL START-UP
Installation, Operation and Maintenance Manual
(This Page Is Intentionally Blank)
Page 60 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Page 61
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
CHAPTER 5
MODE OF OPERATION
Installation, Operation and Maintenance Manual
CHAPTER 5. MODE OF OPER ATION
5.1 INTRODUCTION
The boiler is capable of being operated in any one of six different modes. The following
paragraphs in this Chapter provide descriptions of each of these operating modes. Each boiler
is shipped from the factory tested and configured for the ordered mode of operation. All
temperature related parameters are at their factory default values which work well in most
applications. However, it may be necessary to change certain parameters to customize the unit
to the system environment. A complete listing and descriptions of the temperature related
parameters are included in Appendix A. Factory defaults are listed in Appendix E. Aft er reading
this chapter, parameters can be customized to suit the needs of the specific application.
5.2 INDOOR/OUTDOOR RESET MODE
This mode of operation is based on outside air temperatures. As the out side air temperature
decreases, the supply header temperature will increase and vice versa. For this mode, it is
necessary to install an outside air sensor as well as select a building reference temperature and
a reset ratio.
5.2.1
Reset ratio is an adjustable number from 0.1 to 9.9. Once adjusted, the supply header
temperature will increase by that number for each degree that the outside air temperature
decreases. For instance, if a reset ratio of 1.6 is used, for each degree that outside air
temperature decreases the supply header temperature will increase by 1.6 degrees.
5.2.2
This is a temperature from 40°F to 230°F. Once selected, it is the temperature that the system
references to begin increasing its temperature. For instance, if a reset ratio of 1.6 is used, and
we select a building reference temperature of 70°F, then at an outside temperature of 69°F, the
supply header temperature will increase by 1.6° to 71.6°F.
5.2.3
The outdoor air temperature sensor must be mounted on the North side of the building in an
area where the average outside air temperature is expected. The sensor must be shielded from
the sun's direct rays, as well as direct impingement by the elements. If a cover or shield is used,
it must allow free air circulation. T he sensor may be mounted up to two hundred feet from the
unit. Sensor connections are made at the Input/Output (I/O) Box on the front of the boiler.
Connections are made at the terminals labeled OUTDOOR SENSOR IN and SENSOR
COMMON inside the I/O Box. Use shielded 18 to 22 AWG wire for connections. A wiring
diagram is provided on the cover of the I/O Box. Refer to Chapter 2, paragraph 2.9.1 for
additional wiring information.
Reset Ratio
Building Reference Temperature
Outdoor Air Temperature Sensor Installation
5.2.4
Startup in the Indoor/Outdoor Reset Mode is accomplished as follows:
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Indoor/ Outdoor Startup
Refer to the Indoor/Outdoor reset ratio charts in Appendix D. 1.
Choose the chart corresponding to the desired Building Reference Temperature. 2.
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Go down the left column of the chart to the coldest design outdoor air temperature 3.
expected in your area.
A design engineer typically provides design outdoor air temperature and
supply header temperature data.
Once the design outdoor air temperature is chosen, go across the chart to the desired 4.
supply header temperature for the design temperature chosen in step 3.
Next, go up that column to the Reset Ratio row to find the corresponding reset ratio. 5.
Access the Configuration Menu and scroll through it until the display shows Bldg Ref 6.
Temp. (Building Reference Temperature).
Press the CHANGE key. The display will begin to flash. 7.
Use the ▲ and ▼ arrow keys to select the desired Building Reference Temperature. 8.
Press ENTER to save any changes. 9.
Installation, Operation and Maintenance Manual
NOTE
Next, scroll through the Configuration Menu until the display shows Reset Ratio. 10.
Press the CHANGE key. The display will begin to flash. 11.
Use the ▲ and ▼ arrow keys to select the Reset Ratio determined in step 5. 12.
Press ENTER to save the change. 13.
Refer to paragraph 3.3 for detailed instructions on menu changing.
5.3 CONSTANT SETPOINT MODE
The Constant Setpoint mode is used when a fixed header temperature is desired. Common
uses of this mode of operation include water source heat pump loops, and indirect heat
exchangers for potable hot water systems or processes.
No external sensors are required to operate in this mode. While it is necessary to set the
desired setpoint temperature, it is not necessary to change any other temperature-related
functions. The unit is factory preset with settings that work well in most applications. Prior to
changing any temperature-related parameters, other than the setpoint, it is suggested that an
AERCO representative be contacted. For descriptions of temperature-related functions and their
factory defaults, see Appendices A and E.
5.3.1
The setpoint temperature of the unit is adjustable from 40°F to 240°F. To set the unit for
operation in the Constant Setpoint Mode, the following menu settings must be made in the
Configuration Menu:
Setting the Setpoint
MENU OPTION SETTING
Boiler Mode Constant Setpoint
Internal Setpt Select desired setpoint
Refer to paragraph 3.3 for detailed instructions on changing menu options.
Page 62 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
using ▲ and ▼ arrow
keys (40°F to 240°F)
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CHAPTER 5
MODE OF OPERATION
Installation, Operation and Maintenance Manual
5.4 REMOTE SETPOINT MODES
The unit’s setpoint can be remotely controlled by an Energy Management System (EMS) or
Building Automation System (BAS). The Remot e Setpoint can be driven by a current or voltage
signal within the following ranges:
• 4-20 mA/1-5 Vdc
• 0-20 mA/0-5 Vdc
The factory default setting for the Remote Setpoint mode is 4 - 20 mA/1 - 5 Vdc. With this
setting, a 4 to 20 mA/1 to 5 Vdc signal, sent by an EMS or BAS, is used to change the unit's
setpoint. The 4 mA/1V signal is equal to a 40°F setpoint while a 20 mA /5V signal is equal to a
240°F setpoint. When a 0 to 20 mA/0 to 5 Vdc signal is used, 0 mA is equal to a 40°F setpoint.
In addition to the current and voltage signals described above, the Remote Setpoint mode can
also driven by a RS485 Modbus Network signal from an EMS or BAS.
The Remote Setpoint modes of operation can be used to drive single as well as multiple units.
NOTE
If a voltage, rather than current signal is used to control the
remote setpoint, a DIP switch adjustment must be made on the
PMC Board located in the Control Panel Assembly. Contact your
local AERCO representative for details.
In order to enable the Remote Setpoint Mode, the following menu setting must be made in the
Configuration Menu:
MENU OPTION SETTING
Boiler Mode Remote Setpoint
Remote Signal 4-20mA/1-5V,
0-20mA/0-5V, or
Network
Refer to paragraph 3.3 for detailed instructions on changing menu options.
If the Network setting is selected for RS485 Modbus operation, a valid C omm Address must be
entered in the Setup Menu. Refer to Modbus Communication Manual GF-114 for additional
information.
While it is possible to change the settings of temperature related f unctions, the unit is factory
preset with settings that work well in most applications. It is suggested that an AERCO
representative be contacted, prior to changing any temperature related function settings. For
descriptions of temperature-related functions and their factory defaults, refer to Appendices A
and E.
5.4.1
The only wiring connections necessary for the Remote Setpoint mode are connection of the
remote signal leads from the source to the unit’s I/O Box. The I/O Box is located on the fr ont
panel of the boiler. For either a 4-20mA/0-5V or a 0-20mA/0-5V setting, the connections are
made at the ANALOG IN terminals in the I/O Box. For a Network setting, the connections are
made at the RS-485 COMM terminals in the I/O Box. The signal must be f loat ing, (ungr ounded)
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Remote Setpoint Field Wiring
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at the I/O Box and the wire used must be a two wire shielded pair from 18 to 22 AWG. Polarity
must be observed. The source end of the shield must be connected at the source. When driving
multiple units, each unit’s wiring must conform to the above.
Installation, Operation and Maintenance Manual
5.4.2
Since this mode of operation is factory preset and the setpoint is being externally controlled, no
startup instructions are necessary. In t his mode, the REMOTE LED will light when the external
signal is present.
To operate the unit in the Manual mode, press the AUTO/MAN switch. The REMOTE LED will
go off and the MANUAL LED will light.
To change back to the Remote Setpoint mode, simply press the AUTO/MAN switch. The
REMOTE LED will again light and the MANUAL LED will go off.
Remote Setpoint Startup
5.5 DIRECT DRIVE MODES
The unit’s air/fuel valve position (% open) can be changed by a remote signal which is typically
sent from an Energy Management System (EMS) or from a Building Automation System (BAS).
The Direct Drive mode can be driven by a current or voltage signal within the following ranges:
• 4-20 mA/1-5 Vdc
• 0-20 mA/0-5 Vdc
The factory default setting for the Direct Drive mode is 4-20 mA/1-5 Vdc. With this setting, a 4
to 20 mA signal, sent by an EMS or BAS is used to change the unit’s valve position from 0% to
100%. A 4 mA/1V signal is equal to a 0% valve position, while a 20 mA /5V signal is equal t o a
100% valve position. When a 0-20 mA/0-5 Vdc signal is used, zero is equal to a 0% valve
position.
In addition to the current and voltage signals described above, the Direct Drive mode can also
driven by a RS485 Modbus Network signal from an EMS or BAS.
When in a Direct Drive mode, the unit is a slave to the EMS or BAS and does not have a role in
temperature control. Direct Drive can be used to drive single, or multiple units.
NOTE
If a voltage, rather than current signal is used to control the remote
setpoint, a DIP switch adjustment must be made on the CPU Board located
in the Control Box Assembly. Contact your local AERCO representative for
details.
To enable the Direct Drive Mode, the following menu setting must be made in the Conf iguration
Menu:
MENU OPTION SETTING
Boiler Mode Direct Drive
Remote Signal 4-20mA/1-5V,
0-20mA/0-5V, or Network
Refer to paragraph 3.3 for instructions on changing menu options.
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If the Network setting is selected for RS485 Modbus operation, a valid C omm Address must be
entered in the Setup Menu. Refer to Modbus Communication Manual GF-114 for additional
information.
Installation, Operation and Maintenance Manual
5.5.1
Direct Drive Field Wiring
The only wiring connections necessary for Direct Drive mode are connection of the remote
signal leads from the source to the unit’s I/O Box. For either a 4-20mA/0-5V or a 0-20mA/0-5V
setting, the connections are made at the ANALOG IN terminals in the I/O Box. For a Network
setting, the connections are made at the RS-485 COMM terminals in the I/O Box. The signal
must be floating, (ungrounded) at the I/O Box and the wire used must be a two wire shielded
pair from 18 to 22 AWG. Polarity must be observed. The source end of the shield must be
connected at the source. When driving multiple units, each unit’s wiring must conform to the
above.
5.5.2
Direct Drive Startup
Since this mode of operation is factory preset and the valve position is being externally
controlled, no startup instructions are necessary. In this mode, the REMOTE L ED will light when
the signal is present.
To operate the unit in manual mode, press the AUTO/MAN switch. The REMOTE LED will go
off and the MANUAL LED will light.
To c hange back to the Direct Drive mode, simply press the AUTO/MAN switch. The REMOTE
LED will again light and the MANUAL LED will go off.
5.6 BOILER MANAGEMENT SYSTEM (BMS)
NOTE
BMS Model 168 can utilize either pulse width modulation (PWM) or RS485
Modbus signaling to the Boiler. BMS II Model 5R5-384 can utilize only
RS485 signaling to the Boiler.
The BMS mode of operation is used in conjunction with an AERCO Boiler Management System.
(BMS or BMS II) and the AERCO Control System (ACS). The BMS mode is used when it is
desired to operate multiple units in the most efficient manner possible. For this mode of
operation, a BMS Header Sensor must be installed between 2 and 10 feet downstream of the
LAST boiler in the boiler plant's supply water header. The BMS can control up to 40 boilers; 8
via pulse width modulation (PWM) and up to 32 via Modbus (RS485) net work communication.
For BMS/BMS II programming, operation, and Header Sensor installation details, see GF-108M
(BMS Model 168), GF-124 (BMS II Model 5R5-384), and GF-131 (ACS) Operations Guides. For
operation via an RS485 Modbus network, refer to Modbus Communication Manual GF-114.
To enable the BMS Mode, the following menu settings must be made in the Configuration
Menu:
MENU OPTION SETTING
Boiler Mode Direct Drive
Remote Signal BMS (PWM Input)
Refer to paragraph 3.3 for instructions on changing menu options.
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or
Network (RS485)
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5.6.1 BMS External Field Wiring
Wiring connections for BMS control using PWM signaling are made between connector J P2 on
the BMS panel (boilers 1 through 8), and the B.M.S. (PWM) IN terminals in the I/O Box on the
front of the boilers. Refer to the wiring diagram provided on the cover of the I/O Box.
Wiring connections for RS485 Modbus control are made between connector JP11 on the BMS
(boilers 9 through 40) and the RS485 COMM terminals in the I/O Box on the front of the boilers.
Wire the units using shielded twisted pair wire between 18 and 22 AWG. Observe the proper
polarity for the B.M.S. (PWM) IN and/or RS485 COMM wiring connections. Shields should be
terminated only at the BMS and the boiler end must be left floating. Each unit’s wiring must
conform to the above.
Installation, Operation and Maintenance Manual
5.6.2
This mode of operation is factory preset and the AERCO BMS/BMS II/ACS controls the f iring
rate (air/fuel valve % open position). There are no setup instructions for each individual unit.
To operate the unit in manual mode, press the AUTO/MAN switch. The REMOTE LED will go
off and the MANUAL LED will light
To change back to the BMS mode, simply press the AUTO/MAN switch. The REMOTE LED
will again light and the MANUAL LED will go off.
BMS Setup and Startup
5.7 COMBINATION CONTROL SYSTEM (CCS)
NOTE
Only BMS Model 168 can be utilized for the Combination Mode, not the
BMS II (Model 5R5-384).
A Combination Control System (CCS) is one that uses multiple boilers to cover both spaceheating and domestic hot water needs. An AERCO Boiler Management System (BMS) Model
168 and a Combination Control Panel (CCP), or an ACS and an ACS Relay Panel (optional,
depending on applications) are necessary to configure this system. Typically, an adequate
number of boilers are installed to cover the space-heating load on the design day, however one
or more units are used for the domestic hot water load.
The theory behind this type of system is that the maximum space-heating load and the
maximum domestic hot water load do not occur simultaneously. T herefore, boilers used for the
domestic hot water are capable of switching between constant setpoint and BMS modes of
operation. These boilers are the combination units and are referred to as the combo boilers. The
combo boilers heat water to a constant setpoint temperature. That water is then circulated
through a heat exchanger in a domestic hot water storage tank.
When the space-heating load is such that all the space-heating boilers are at the 100% valve
position, the BMS/ACS will then ask the Combination Control Panel for the domest ic boilers to
become space-heating boilers, provided the domestic hot water load is sa t isf ied, t he c ombo (hot
water) boilers will then become space-heating boilers. If the domestic hot water load is not
satisfied, the combo boiler(s) remain on the domestic hot water load. If the combo boilers
switch over to space heating, but there is a call for domestic hot water, the combo units will
resume heating water for domestic needs.
When the combo units are satisfying the domestic load they are in con stant setpoint mode of
operation. When the combo units switch over to space heating, their mode of operation changes
to the BMS mode. For more information concerning the operation of the Combination Control
Panel see the AERCO CCP-1 literature (BMS 168 applications) and TAG-0050 (ACS).
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Installation, Operation and Maintenance Manual
5.7.1
Wiring for this system is between the BMS Model 168 panel, the CCP and the B.M.S. (PW M) IN
terminals in the I/O Box. For ACS applications, the wiring is between the ACS Panel, the ACS
Relay Panel (optional, depending on application) and the W ire the units using a shielded twisted
pair of 18 to 22 AWG wire. When wiring multiple units, each unit’s wiring must conform to the
above. For a complete CCP system wiring diagram see the AERCO CCP-1 literature168
applications) and TAG-0050 (ACS).
5.7.2
Setup for the Combination Mode requires entries to be made in the Configuration Menu for
boiler mode, remote signal type and setpoint. The setpoint is adjustable from 40°F to 240°F.
Enter the following settings in the Configuration Menu:
Refer to paragraph 3.3 for instructions on changing menu options.
Combination Control System Field Wiring
Combination Control System Setup and Startup
MENU OPTION SETTING
Boiler Mode Combination
Remote Signal BMS (PWM Input)
Internal Setpt 40°F to 240°F
While it is possible to change other temperature-related f unctions for combination mode, thes
functions are preset to their factory default values. These default settings work well in most
applications. It is suggested that AERCO be contacted prior to changing settings ot her than the
unit’s setpoint. For a complete listing of temperature related function defaults, see Appendix E.
To set the unit to the manual mode, press the AUTO/MAN switch. The MANUAL LE D will light.
To set the unit back to the auto mode, pr es s t he AUTO/MAN switch. The MANUAL LED will go
off and the REMOTE LED will light.
When the boiler is switched to BMS mode, the AERCO BMS/ACS controls the valve position.
There are no setup requirements to the boiler(s) in this mode.
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Installation, Operation and Maintenance Manual
(This page is intentionally blank)
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CHAPTER 6
SAFETY DEVICE TESTING
Installation, Operation and Maintenance Manual
CHAPTER 6. SAFETY DEVICE TESTING
6.1 TESTING OF SAFETY DEVICES
Periodic safety device testing is required to ensure that the control system and safety devices
are operating properly. The boiler control system comprehensively monitors all combustionrelated safety devices before, during and after the start sequence. The following tests check to
ensure that the system is operating as designed.
Operating controls and safety devices should be tested on a regular basis or following service or
replacement. All testing must conform to local codes such as ASME CSD-1.
NOTE
MANUAL and AUTO modes of operation are required to perform the
following tests. For a complete explanation of these modes, see Chapter 3.
NOTE
It will be necessary to remove the front door and side panels from the unit
to perform the following tests.
WARNING
ELECTRICAL VOLTAGES IN THI S SYSTEM MAY INCLUDE 120 AND 24
VOLTS AC. Power MUST be Removed Prior to Perf orming Wire Removal
OR OTHER Test Procedures that Can Result in Electrical Shock.
6.2 LOW GAS PRESSURE FAULT TEST
Refer to Figure 6-1 and ensure that the leak detection ball valve located at the high gas
pressure switch is closed.
Remove the 1/4“ plug from the ball valve at the low gas pressure switch shown in the 1.
lower portion of Figure 6-1.
Install a 0 – 16 “ W.C. manometer or a W.C. gauge where the 1/4" plug was removed. 2.
Slowly open the ball valve near the low gas pressure switch. 3.
Place the unit in Manual Mode and adjust the air/fuel valve position (% open) between 4.
25 and 30%.
While the unit is firing, slowly close the external manual gas shut-off valve. 5.
The unit should shut down and display a LOW GAS PRESSURE fault message at 6.
approximately 2.6” W.C. The FAULT indicator should also start flashing.
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SSO
1/4” NPT PLUG
TEST/CALIBRATION)
HIGH GAS
SWITCH
1/4” NPT PLUG
PRESSURE TEST)
1/4” NPT PLUG
PRESSURE TEST)
CHAPTER 6
SAFETY DEVICE TESTING
PRESSURE
HIGH GAS BALL
VALVE
Installation, Operation and Maintenance Manual
MANUAL SHUTOFF VALVE
(INSTALL
MONOMETER HERE
FOR HIGH GAS
RSI
SOLENOID
VALVE
(INSTALL
MONOMETER HERE
FOR RSI PRESSURE
RSI
PRESSURE
REGULATOR
Fully open the external manual gas shut-off valve and press the CLEAR button on the 7.
Control Box.
AIR/FUEL
VALVE
RSI GAS
VALVE
RSI BLEEDOFF VALVE
Figure 6-1: Low & High Gas Pressure Testing
TO
LOW GAS
PRESSURE
SWITCH
(INSTALL
MONOMETER HERE
FOR LOW GAS
GAS INLET
The fault message should clear and the FAULT indicator should go off. The unit should 8.
restart.
Upon test completion, close the ball valve and remove the manometer. Replace the 1/4“ 9.
plug removed in step 1.
6.3 HIGH GAS PRESSURE TEST
To simulate a high gas pressure fault, refer to Figure 6-1 and proceed as follows:
Remove the 1/4“ plug from the leak detection ball valve shown in Figure 6-1. 1.
Install a 0 – 16” W.C. manometer (or W.C. gauge) where the 1/4” plug was removed. 2.
Slowly open the leak detection ball valve 3.
Start the unit in Manual mode at a valve position (firing rate) between 25 and 30%. 4.
Slowly increase the gas pressure using the adjustment screw on the SSOV. 5.
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The unit should shut down and display a HIGH GAS PRESSURE fault message when 6.
the gas pressure exceeds 4.7” W.C. The FAULT indicator should also start flashing.
Reduce the gas pressure back to 3.0” W.C. 7.
Press the CLEAR button on the Control Box to clear the fault. 8.
The fault message should clear and the FAULT indicator should go off. The unit should 9.
restart.
Upon test completion, close the ball valve and remove the manometer. Replace the 10.
1/4“ plug removed in step 1.
Installation, Operation and Maintenance Manual
6.4 LOW WATER LEVEL FAULT TEST
To simulate a low water level fault:
Set the ON/OFF switch to the OFF position 1.
Close the water shut-off valves in the supply and return piping to the unit. 2.
Slowly open the drain valve on the rear of the unit. If necessary the unit’s relief valve 3.
may be opened to aid in draining.
Continue draining the unit until a LOW WATER LEVEL fault message is displayed and 4.
the FAULT indicator flashes.
Place the unit in the Manual Mode and raise the valve position above 30%. 5.
Set the ON/OFF switch to the ON position. The READY light should remain off and the 6.
unit should not start. If the unit does start, shut the unit off immediately and refer fault to
qualified service personnel.
Close the drain and pressure relief valve used in draining the unit. 7.
Open the water shut-off valve in the return piping to the unit. 8.
Open the water supply shut-off valve to the unit to refill. 9.
After the shell is full, press the LOW WATER LEVEL RESET button to reset the low 10.
water cutoff.
Press the CLEAR button to reset the FAULT LED and clear the displayed error 11.
message.
Set the ON/OFF switch to the ON position. The unit is now ready for operation. 12.
6.5 WATER TEMPERATURE FAULT TEST
A high water temperature fault is simulated by adjusting the automatic over-temperature switch.
This switch is accessible from the front of the unit as shown in Figure 6-2.
Start the unit in the normal operating mode. Allow the unit to stabilize at its setpoint. 1.
Lower the adjustable over-temperature switch setting to match the displayed OUTLET 2.
TEMPERATURE.
Once the adjustable over-temperature switch setting is approximately at, or just below, 3.
the actual outlet water temperature, the unit should shut down. The FAULT indicator
should start flashing and a HIGH WATER TEMP SWITCH OPEN fault message should
be displayed. It should not be possible to restart the unit.
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FRONT VIEW
ADJUSTABLE
TEMPERATURE
LIMIT SWITCH
RESET BUTTON
FOR MANUAL
TEMPERATURE
LIMIT SWITCH
SEE
DETAIL “A”
DETAIL “A”
F
Alarm
DIGITAL OVER-
TEMPERATURE
ALARM SWITCH
CHAPTER 6
SAFETY DEVICE TESTING
Installation, Operation and Maintenance Manual
Reset the adjustable over-temperature switch to its original setting. 4.
The unit should start once the adjustable temperature limit switch setting is above the 5.
actual outlet water temperature.
Page 72 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Figure 6-2: Temperature Limit Switch Setting
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Once the adjustable over-temperature switch setting is approximately at, or just below, 6.
the actual outlet water temperature, the unit should shut down. The FAULT indicator
should start flashing and a HIGH WATER TEMP SWITCH OPEN fault message should
be displayed. It should not be possible to restart the unit.
Reset the adjustable over-temperature switch to its original setting. 7.
The unit should start once the adjustable temperature limit switch setting is above the 8.
actual outlet water temperature.
Installation, Operation and Maintenance Manual
6.6 INTERLOCK TESTS
The unit is equipped with two interlock circuits called the Remote Interlock and Delayed
Interlock. Terminal connections for these circuits are located in the I/O Box (Figure 2-9) and are
labeled REMOTE INTL’K IN and DELAYED INTL’K IN. These circuits can shut down the unit in
the event that an interlock is opened. These interlocks are shipped from the factory jumpered
(closed). However, each of these interlocks may be utilized in the field as a remote stop and
start, an emergency cut-off, or to prove that a device such as a pump, gas booster, or louver is
operational.
6.6.1
6.6.2
REMOTE INTERLOCK
Remove the cover from the I/O Box and locate the REMO TE INTL’K IN terminals. 1.
Start the unit in the Manual Mode and set the valve position between 25% and 30%. 2.
If there is a jumper across the REMOTE INTL’K IN terminals, remove one side of the 3.
jumper. If the interlock is being controlled by an external device, either open the
interlock via the external device or disconnect one of the wires leading to the external
device.
The unit should shut down and display INTERLOCK OPEN. 4.
Once the interlock connection is reconnected, the INTERLOCK OPEN message should 5.
automatically clear and the unit should restart.
DELAYED INTERLOCK
Remove the cover from the I/O Box and locate the DELAYED INTL’K IN terminals. 1.
Start the unit in the Manual Mode at a valve position between 25% and 30%. 2.
If there is a jumper across the DELAYED INTL’K IN terminals, remove one side of the 3.
jumper. If the interlock is connected to a proving switch of an external device,
disconnect one of the wires leading to the proving switch.
The unit should shut down and display a DELAYED INTERLOCK OPEN fault message. 4.
The FAULT LED should be flashing.
Reconnect the wire or jumper removed in step 3 to restore the interlock. 5.
Press the CLEAR button to reset the fault 6.
The unit should start. 7.
6.7 FLAME FAULT TESTS
Flame faults can occur during ignition or while the unit is already running. To simulate each of
these fault conditions, proceed as follows:
Set the ON/OFF switch to the OFF position. 1.
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PARTIAL LEFT SIDE VIEW
BLOWER
PROOF
SWITCH
BLOCKED
INLET
SWITCH
AIR
INLET
AIR/FUEL
VALVE
SSOV
MANUAL
GAS
SHUTOFF
VALVE
CHAPTER 6
SAFETY DEVICE TESTING
Place the unit in the Manual Mode and set the valve position between 25% and 30%. 2.
Close the manual gas shutoff valve located between the Safety Shut-Off Valve (SSOV) 3.
and the Air/Fuel Valve (see Figure 6-3).
Installation, Operation and Maintenance Manual
Figure 6-3: Manual Gas Shut-Off Valve Location
Set the ON/OFF switch to the ON position to start the unit. 4.
The unit should shut down after reaching the Ignition cycle and display FLAME LOSS 5.
DURING IGN.
Open the valve previously closed in step 3 and press the CLEAR button. 6.
Restart the unit and allow it to prove flame. 7.
Once flame is proven, close the manual gas valve located between the SSOV (Figure 6-8.
3) and the Air/Fuel Valve.
The unit should shut down and execute an IGNITION RETRY cycle by performing the 9.
following steps:
a. The unit will execute a shutdown purge cycle for a period of 15 seconds and display
WAIT FAULT PURGE.
b. The unit will execute a 30 second re-ignition delay and display WAIT RETRY
PAUSE.
c. The unit will then execute a standard ignition sequence and display WAIT IGNIT ION
RETRY.
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CHAPTER 6
SAFETY DEVICE TESTING
Installation, Operation and Maintenance Manual
Since the manual gas shutoff valve is still closed, the un it will fail the ignition retry 10.
sequence. Therefore, it will shut down and display FLAME LOSS DURING IGNITION
following the failed ignition retry cycle.
Open the valve previously closed in step 8. 11.
Press the CLEAR button. The unit should restart and fire. 12.
6.8 AIR FLOW FAULT TESTS
These tests check the operation of the Blower Proof Switch and Block ed Inlet Switch shown in
Figure 6-3.
Disable the blower output drive voltage as follows: 1.
a. Press the MENU key until CONFIGUR-ATION MENU is displayed.
b. Press the ▲ arrow key until the ANA-LOG OUTPUT function is displayed, then press
the CHANGE key.
c. Press the ▼ arrow key until OFF is displayed, then press the ENTER key.
Start the unit in the Manual Mode at a valve position between 25% and 30%. 2.
The unit should shut down and execute an IGNITION RETRY cycle by performing the 3.
following steps:
a. The unit will execute a 30 second re-ignition delay and display WAIT RETRY
PAUSE.
b. The unit will then execute a standard ignition sequence and display WAIT IGNITI ON
RETRY.
The unit should perform one IGNITION RETRY cycle and then shut down, since the 4.
blower is disabled. The unit will then display AIRFLOW FAULT DURING PURGE.
Re-enable the blower output drive voltage by performing the following steps: 5.
a. Press the MENU key until CONFIGURATION MENU is displayed.
b. Press the ▲ arrow key until the ANA-LOG OUTPUT function is displayed, then press
the CHANGE key.
c. Press the ▲ arrow key until VALVE POSITION 0-10V is displayed, then press the
ENTER key.
Once the unit has proved flame, turn off the blower by going to the Configuration Menu, 6.
Analog Output menu item and select OFF.
The Blower Proof Switch will open and the blower should stop. The unit should shut 7.
down and display AIRFLOW FAULT DURING RUN.
Go to the Configuration Menu, Analog Output item and select VALVE POSITION 0-10v. 8.
Press the CLEAR button. The unit should restart. 9.
Next, check the Blocked Inlet Switch by first noting the current position of the Iris Air 10.
Damper and then closing the Damper to position 8.
.The unit should shut down and again display AIRFLOW FAULT DURING RUN. 11.
Return the Iris Air Damper to its previous setting. 12.
Press the CLEAR button. The unit should restart. 13.
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 75 of 166
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ACTUATOR
COVER
SCREW
SSOV
ACTUATOR
COVER
CHAPTER 6
SAFETY DEVICE TESTING
Installation, Operation and Maintenance Manual
6.9 SSOV PROOF OF CLOSURE SWITCH
The SSOV shown in Figure 6-1 contains the proof of closure switch. The proof of closure switch
circuit is checked as follows:
Set the unit’s ON/OFF switch to the OFF position. 1.
Place the unit in Manual Mode and set the valve position between 25% and 30%. 2.
Refer to Figure 6-1 and locate the SSOV. 3.
Remove the cover from the SSOV by loosening the screw shown in Figure 6-4. Lift off 4.
the cover to access the terminal wiring connections.
Disconnect wire #148 from the SSOV to “open” the proof of closure switch circuit. 5.
The unit should fault and display SSOV SWITCH OPEN. 6.
Replace wire #148 and press the CLEAR button. 7.
Set the ON/OFF switch to ON to start t he unit. 8.
Remove the wire again when the unit reaches the purge cycle and PURGING is 9.
displayed.
The unit should shut down and display SSOV FAULT DURING PURGE. 10.
Replace the wire on the SSOV and press the CLEAR button. The unit should restart. 11.
Figure 6-4: SSOV Actuator Cover Location
6.10 PURGE SWITCH OPEN DURING PURGE
The Purge Switch (and Ignition Switch) is located on the Air/Fuel Valve. T o check the switch,
proceed as follows:
Page 76 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
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Benchmark 1.5LN Low NOx Boiler
AIR/FUEL VALVE COVER
(ROTATE CCW TO REMOVE)
CHAPTER 6
SAFETY DEVICE TESTING
Installation, Operation and Maintenance Manual
Set the unit’s ON/OFF switch to the OFF position. Place the unit in manual mode and set 1.
the valve position between 25% and 30%.
Remove the Air/Fuel Valve cover by rotating the cover counterclockwise to unlock it and 2.
then lift up (see Figure 6-5).
Remove one of the two wires (#171 or #172) from the Purge Switch (Figure 6-6). 3.
Initiate a unit start sequence. 4.
The unit should begin it’s start sequence, then shut down and display PRG SWITCH 5.
OPEN DURING PURGE.
Replace the wire on the Purge Switch and depress the CLEAR butt on. The unit should 6.
restart.
6.11 IGNITION SWITCH OPEN DURING IGNITION
The Ignition Switch (and the Purge Switch) is located on the Air/Fuel Valve. To check the
switch, proceed as follows:
Set the unit’s ON/OFF switch to the OFF position. 1.
Place the unit in Manual Mode and set the valve position between 25% and 30%. 2.
Remove the Air/Fuel Valve cover (Figure 6-5) by rotating the cover counterclockwise to 3.
unlock and lift up to remove.
Remove one of the two wires (#169 or #170) from the Ignition Switch (Figure 6-6). 4.
Initiate a unit start sequence. 5.
The unit should begin its start sequence and then shut down and display IGN SWITCH 6.
OPEN DURING IGNITION.
Replace the wire on the Ignition Switch and press the CLEAR button. The unit should 7.
restart.
Figure 6-5: Air/Fuel Valve Cover Location
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 77 of 166
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Benchmark 1.5LN Low NOx Boiler
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STEPPER
MOTOR
DIAL
172
171
169
170
IGNITION
POSITION
SWITCH
PURGE
POSITION
SWITCH
AIR
IN
TO
BLOWER
CHAPTER 6
SAFETY DEVICE TESTING
Installation, Operation and Maintenance Manual
Figure 6-6: Air/Fuel Valve Purge and Ignition Switch Locations
6.12 SAFETY PRESSURE REL IEF VALVE TEST
Test the safety Pressure Relief Valve in accordance with ASME Boiler and Pressure Vessel
Code, Section VI.
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Page 79
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Benchmark 1.5LN Low NOx Boiler
Labor
Time
7.2
Igniter-Injector (58023)
*Inspect
Inspect
Replace
15 mins.
7.3
Flame Detector (24356-1)
*Inspect
Inspect
Replace
15 mins.
Combustion Calibration &
RSI Regulator Adjustment
Inspect &
Clean
CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
CHAPTER 7. MAINTENANCE
7.1 MAINTENANCE SCHEDULE
The unit requires regular routine maintenance to keep up efficiency and reliability. For best
operation and life of the unit, the following routine maintenance procedures should be performed
in the time periods specified in Table 7-1. See Appendix I for a complete CSD-1 inspection
check list.
In order to perform the maintenance tasks specified in Table 7-1, the following maintenance kits
are available through your local AERCO Sales Representative:
• Annual Maintenance Kit, Part No. 58025-01
• 24-Month Waterside/Fireside Inspection Kit, Part No. 58025-05 (See NOTE below)
NOTE
The 24-Month Waterside/Fireside Inspection Kit also includes the items
contained in the Annual Maintenance Kit. Therefore, only Kit Part No.
58025-05 is required when performing the waterside/fireside inspections.
Appendix K contains recommended spare parts lists for maintenance of the boiler.
WARNING
TO AVOID PERSONAL INJURY, PRIOR TO SERVICING ENSURE THAT
THE FOLLOWING GUIDELINES ARE STRICTLY OBSERVED:
• DISCONNECT THE AC SUPPLY BY TURNING OFF THE SERVICE
SWITCH AND AC SUPPLY CIRCUIT BRE AKER.
• SHUT OFF THE GAS SUPPLY AT THE MANUAL SHUT-OFF VALVE
PROVIDED WITH THE UNIT
• ALLOW THE UNIT TO COOL TO A SAFE WATER TEMPERATURE
TO PREVENT BURNING OR SCALDING
Table 7-1: Maintenance Schedule
Paragraph Item 6 Mos. 12 Mos. 24 Mos.
7.4
*Check Check 1 hr.
7.5 Testing of Safety Devices
7.6 Burner Inspect 2 hrs.
7.7 Condensate Drain Trap *Inspect
*Only performed after initial 6 month period after initial startup.
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 79 of 166
See CSD-1
Chart in
Appendix I
20 mins.
30 mins.
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OMM-0041 0E
AIR/FUEL
VALVE
STAGED
IGNITION
ASSEMBLY
FLAME
DETECTOR
IGNITOR-
INJECTOR
BLOWER
BURNER
PLATE
BURNER
CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
7.2 IGNITER-INJECTOR
The igniter-injector (part no. 58023) is located on the burner plate at the top of the boiler. In
addition to providing the ignition spark required to light the burner, the igniter-injector also
contains a gas injector tube which connects to the staged ignition assembly. Figure 7-1 shows
the complete burner assembly removed from the boiler and indicates the location of the igniterinjector flame detector and other related components.
The igniter-injector may be hot, therefore, care should be exercised to avoid burns. It is easier to
remove the igniter-injector from the unit after the unit has cooled to room temperature.
Figure 7-1: Benchmark 1.5LN Burner Assembly (Shown Removed from Boiler)
To inspect/replace the Igniter:
Set the ON/OFF switch on the control panel, to the OFF position. Disconnect AC power 1.
from the unit
Remove the side and top panels from the unit. 2.
Disconnect the cable from the igniter-injector (Figure 7-1). 3.
Refer to the partial exploded view in Figure 7-2. Using a 7/16” open-end wrench, 4.
disconnect the compression nut securing the gas injector tube of the igniter-injector to
the elbow of the staged ignition assembly. Disconnect the staged ignition assembly from
the igniter-injector.
Page 80 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
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Benchmark 1.5LN Low NOx Boiler
STAGED
IGNITION
ASSEMBLY
FLAME
DETECTOR
IGNITOR-
INJECTOR
BURNER
PLATE
COMPRESSION
FITTING & ELBOW
FLAME
DETECTOR
GASKET
INDEXING
WASHERS
(QTY = 0-3
AS REQ’D)
120
IGNITOR-
INJECTOR
GAS
INJECTOR
TUBE
BLOWER
BURNER
PLATE
CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
Figure 7-2
Igniter-Injector & Flame Detector Mounting Details
Next, loosen and remove the igniter-injector from the burner plate using a 1" open-end 5.
wrench.
Check the igniter-injector for evidence of erosion or carbon build-up. If there is evidence 6.
of substantial erosion or carbon build-up, the igniter-injector should be replaced. If
carbon build-up is present, clean the component using fine emery cloth. Repeated
carbon build-up is an indication that the combustion settings of the unit should be
checked. Refer to Chapter 4 for combustion calibration procedures.
Prior to reinstalling the igniter-injector, a high temperature, conductive, anti-seize com-7.
pound must be applied to the threads.
NOTE
If a replacement igniter-injector (part no. 58023) is being installed, a
compression nut containing a built-in ferrule will be included with the
replacement part. If needed, 3 indexing washers are also included These
washers may be needed to properly position the gas injector tube of the
igniter-injector within the 120° angle range shown in Figure 7-3.
Figure 7-3: Igniter-Injector Orientation
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CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
Reinstall the igniter-injector in the burner plate. Torque to 15 ft-lbs. Do not over tighten. 8.
Connect the staged ignition assembly to the gas injector tube of the igniter-injector by 9.
securing the compression nut to the elbow of the staged ignition assembly.
Reconnect the igniter-injector cable. 10.
Reinstall the side and top panels on the unit. 11.
7.3 FLAME DETECTOR
The flame detector (part no. 24356-1) is located on the burner plate at the top of the unit (see
Figures 7-1 and 7-2). The flame detector may be hot. Allow the unit to cool sufficiently before
removing the flame detector.
To inspect or replace the flame detector:
Set the ON/OFF switch on the control panel, to the OFF position. Disconnect AC power 1.
from the unit.
Remove the side and top panels from the unit. 2.
Disconnect the flame detector lead wire. 3.
Remove the two (2) screws securing the flame detector to the plate (Figure 7-2 on 4.
previous page). The flame detector is secured to the burner plate with one (1) #10-32
screw and one (1) #8-32 screw.
Remove the flame detector and gasket from the burner plate. 5.
Thoroughly inspect the flame detector. If eroded, the detector should be replaced. 6.
Otherwise clean the detector with a fine emery cloth.
Reinstall the flame detector and flame detector gasket. 7.
Reconnect the flame detector lead wire. 8.
Reinstall the side and top panels on the unit. 9.
7.4 COMBUSTION CALIBRATION & RSI REGUL ATOR ADJUSTMENT
The Combustion Calibration settings and RSI Regulator adjustment must be checked at the
intervals shown in Table 7-1 as part of the maintenance requirements. Ref er to Chapter 4 for
combustion calibration instructions. Refer to paragraph 7.4. 1, below, for RSI regulator test and
calibration instructions.
7.4.1
The BMK1.5LN unit has a RSI (Regulated Staged Ignition) system in the gas train that should
be pressure tested annually. If the pressure is above 5.0” w.c. or below 3.0” w.c., then the RSI
pressure regulator must be recalibrated per paragraph 7.4.1.2.
RSI Regulator Pressure
7.4.1.1 RSI Regulator Pressure Test
The RSI regulator test is performed as follows:
Ensure that gas supply shut-off valve upstream of the unit is still turned OFF. 1.
Turn OFF electrical power to the system. 2.
CLOSE the following valves in the unit’s gas train (refer to Figure 7-4): 3.
• RSI Gas Supply Valve
• RSI Bleed-off Valve
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CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
• Manual Shut-off Valve (between the Air/Fuel Valve and the SSOV).
Remove the pipe plug from the 1/4” NPT port on the outlet side of the RSI regulator and 4.
insert a NPT-to-barbed adapter fitting (see Figure 7-4).
Attach one end of the plastic tubing to the barbed fitting and the other end to the 16” 5.
W.C. manometer.
Remove the cap from the RSI Pressure Regulator and rotate the regulator adjustment 6.
(beneath cap) counterclockwise (CCW) to its lowest possible pressure setting that will
allow the cap to be installed.
OPEN the main gas supply upstream of the unit. 7.
Turn ON electrical power to the system. 8.
Slowly OPEN the RSI Gas Supply Valve and observe the reading on the manometer. It 9.
should have a reading of less than 8.0” w.c.
Start the boiler in MANUAL Mode. Observe the manometer pressure when the RSI 10.
solenoid “clicks” open after purge. It should now provide a reading of less than 5.0” w.c.,
but not less than 3.0” w.c..
Look into the observation port in the top head and ensure that you observe the orange 11.
glow of the RSI flame during the ignition trial period.
If the pressure is within specifications, return the unit to service. Make sure that the unit 12.
is operating in AUTO Mode. The “MAN” light in the upper left of the control box should
NOT be lit when in AUTO Mode.
If the RSI regulator is NOT within specifications, proceed to paragraph 7.4.1.2 (RSI 13.
Regulator Calibration) and initiate the pressure calibration procedures
7.4.1.2 RSI Regulator Calibration
RSI regulator calibration is performed as follows:
Ensure that gas supply shut-off valve upstream of the unit is still turned OFF. 1.
Turn OFF electrical power to the system. 2.
CLOSE the following valves in the unit’s gas train (refer to Figure 7-4): 3.
• RSI Gas Supply Valve
• RSI Bleed-off Valve
• Manual Shut-off Valve (between the Air/Fuel Valve and the SSOV).
Remove the pipe plug from the 1/4” NPT port on the outlet side of the RSI regula tor, 4.
insert NPT-to-barbed adapter fitting, and insert tube from the 16” w.c. manometer.
Remove the cap from the RSI Pressure Regulator and rotate the regulator adjustment 5.
(beneath cap) counter-clockwise (CCW) to its lowest possible pressure setting that will
allow the cap to be installed.
OPEN the main gas supply upstream of the unit. 6.
Turn ON electrical power to the system. 7.
Slowly OPEN the RSI Gas Supply Valve and observe the reading on the manometer. It 8.
should have a reading of less than 8.0” w.c.
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CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
Start the boiler in MANUAL Mode. Observe the manometer pressure when the RSI 9.
solenoid “clicks” open after purge. The manometer should now provide a reading of less
than 5.0” w.c.
Look into the observation port in the top head and ensure that you observe the orange 10.
glow of the RSI flame during the ignition trial period.
NOTE
If you don’t see the orange glow, contact AERCO technical support to
ascertain the problem. If you DO see it, proceed to the next step.
If the manometer reading is less than 3.0” w.c., increase the regulator setting by rotating 11.
the adjustment screw clockwise (CW).
Repeat steps 8 through 11 until the gas pressure at the outlet of the RSI regulator reads 12.
between 3.0” w.c. and 4.0” w.c. on the monometer.
Once the pressure reading is between 3.0” w.c. and 4.0” w.c., conduct at least three safe 13.
RSI ignitions while observing the observation port. Assure the igniter lights immediately
with a strong orange flame after the Staged Ignition Solenoid Valve opens.
NOTE
Clear any Flame Loss During Ignition messages during the tests by
pressing The CLEAR key on control panel.
Close the external gas supply and RSI Staged Ignition Gas Valves. Disconnect the 14.
manometer, tubing and barbed fitting from the 1/4” NPT port hole.
Bleed off any remaining pressure using the RSI bleed-off valve, then ensure this valve is 15.
closed.
Replace the 1/4” plug in place of the barbed fitting. 16.
OPEN the gas supply upstream of the unit. 17.
Ensure power is restored and Boiler turned on in MANUAL Mode. 18.
Open the Manual Shut-off Gas Valve (to the Air/Fuel Valve) and assure a smooth light 19.
off. Perform this test three times.
Leak test the RSI line after the first solenoid valve. 20.
Refer to Chapter 4, paragraph 4.4 and perform the Combustion Calibration procedures.. 21.
Return the unit to service. Make sure that the unit is operating in AUTO Mode. The 22.
“MAN” light in the upper left of the control box should NOT be lit in AUTO Mode.
Page 84 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
Page 85
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
Part No.
Description
81063
Burner Gaskets (Qty=2)
81048
Flame Detector Gasket
81064
Blower Gasket
CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
Figure 7-4: RSI Manometer Installation Location
7.5 SAFETY DEVICE TESTING
Systematic and thorough tests of the operating and safety devices should be performed to
ensure that they are operating as designed. Certain code requirements, such as ASME CSD-1,
require that these tests be performed on a scheduled basis. Test schedules must conform to
local jurisdictions. The results of the tests should be recorded in a log book. See Chapter 6Safety Device Testing Procedures.
7.6 BURNER ASSEMBLY INSPECTION
The burner assembly (part no. 24012) is located at the top of the unit's heat exchanger. The
burner assembly may be hot. Therefore, allow the unit to cool sufficiently before removing the
burner assembly. It should be noted that the complete burner assembly also includes the blower
and air/fuel valve assemblies for the unit.
The following parts will be required for reassembly after burner inspection:
To inspect or replace the burner assembly:
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 85 of 166
Page 86
Benchmark 1.5LN Low NOx Boiler
GF-120
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BLOWER
PROOF
SWITCH
BURNER
PLATE
BLOWER
IGNITER-
INJECTOR
HOSE
CLAMP
FLAME
DETECTOR
STAGED
IGNITION
ASSEMBLY
3/8-16
HEX NUTS
(8)
1/2" BOLTS
& NUTS (4)
AIR/FUEL
VALVE
BLOCKED
INLET
SWITCH
10-32 x 1 /2" LG
GROUNDING
SCREW
CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
Set the ON/OFF switch on the control panel, to the OFF position. Disconnect AC power 1.
from the unit and turn off the gas supply.
Remove the side and top panels from the unit. 2.
Disconnect the lead wire from the flame detector installed on the burner plate. See 3.
Figure 7-4.
Figure 7-4: Burner Assembly Mounting Details
Remove the two (2) screws securing the flame detector to the plate. The flame detector 4.
is secured to the burner plate with one (1) #10-32 screw and one (1) #8-32 screw.
Remove the flame detector and gasket from the burner plate. 5.
Disconnect the cable from the igniter-injector. 6.
Using a 7/16” open-end wrench, disconnect the compression nut securing the gas 7.
injector tube of the igniter-injector to the elbow of the staged ignition assembly (see
Figure 7-2). Disconnect the staged ignition assembly from the igni ter-injector.
Next, loosen and remove the igniter-injector from the burner plate using a 1" open-end 8.
wrench.
Disconnect the unit wiring harness connectors from the air/fuel valve and blower motor. 9.
Disconnect the wire leads connected to the blower proof switch and blocked inlet switch 10.
(Figures 7-4 & 7-5).
Remove the 10-32 x 1/2" long. grounding screw from the burner plate (Figures 7-4 and 11.
7-5).
Disconnect the gas train from the air/fuel valve by removing the four (4) 1/2” bolts and 12.
nuts (Figure 7-4).
Page 86 of 166 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 PR1:10/18/12
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Benchmark 1.5LN Low NOx Boiler
CHAPTER 7
MAINTENANCE
Disconnect the flex hose from the air/fuel valve by loosening the hose clamp. 13.
Remove the four (4) 5/16-18 hex head screws securing the blower to the burner plate 14.
(Figure 7-5).
Remove the blower and air/fuel valve from the burner plate by lifting straight up. Also, 15.
remove the blower gasket.
Remove the eight (8) 3/8-16 nuts from the burner flange (Figure 7-4) using a 9/16” 16.
wrench.
The burner assembly is heavy, weighing approximately 25 pounds.
Remove the burner assembly from burner flange by pulling straight up. 17.
Remove and replace the two (2) burner gaskets. 18.
During reassembly, apply high-temperature, anti-seize lubricant to the
threads of the igniter-injector and grounding screw. Also, ensure that the
igniter-injector is properly positioned as indicated in Figure 7-3. Torque the
igniter-injector to 15 ft-lbs.
Installation, Operation and Maintenance Manual
NOTE
NOTE
Beginning with the burner assembly removed in step 17, reinstall all the components in 19.
the reverse order that they were removed.
Ensure that the igniter-injector and flame detector cutouts in the burner plate are 20.
properly aligned with the heat exchanger top flange.
PR1: 10/18//12 AERCO International Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288 Page 87 of 166
Page 88
Benchmark 1.5LN Low NOx Boiler
GF-120
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AIR/FUEL
VALVE
BLOWER
IGNITOR-
INJECTOR
FLAME
DETECTOR
STAGED IGNITION
ASSEMBLY
BURNER GASKET
BURNER GASKET
BURNER
HEX HEAD SCREWS (4)
BLOWER
GASKET
BURNER
PLATE
BLOWER
PROOF
SWITCH
BLOCKED
INLET
SWITCH
GROUNDING
SCREW
CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
Figure 7-4: Burner Assembly Exploded View
7.7 CONDENSATE DRAIN TRAP
The Benchmark 1.5 Boiler contains a condensate trap as shown in Chapter 2, Figure 2-5. T he
trap is located external to the unit and attached to the drain pipe from the exhaust manifold. This
trap should be inspected and, if necessary, cleaned to ensure proper operation.
There are two slightly different types of condensate traps that may be used
in your configuration; an older style without an inlet adapter, and a newer
style with a built-in adapter (see Figure 7.5). Maintenance is the same,
except that the newer style does not need an orifice gasket (Step 6).
To inspect and clean the trap, proceed as follows:
Disconnect the external condensate trap by loosening the union pipe connection 1.
between the trap and the exhaust manifold drain pipe.
Remove the connections on the inlet and outlet sides of the condensate trap shown in 2.
Figure 7-5.
Loosen the four (4) thumbscrews securing the cover on the condensate trap. Remove 3.
the cover.
Remove the float from the condensate trap. 4.
NOTE
Remove the orifice gasket from the trap. 5.
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Page 89
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
CHAPTER 7
MAINTENANCE
Thoroughly clean the trap, float and gasket. Also inspect the drain piping for blockage. If 6.
the trap cannot be thoroughly cleaned, replace the trap.
After the above items have been inspected and thoroughly cleaned, replace the orifice 7.
gasket and float in the condensate trap and replace the trap cover.
Reassemble all piping and hose connections to the condensate trap inlet and outlet. 8.
Reconnect trap to exhaust manifold drain.
Installation, Operation and Maintenance Manual
Figure 7-5: External Condensate Trap
7.8 SHUTTING THE BOILER DOWN FOR AN EXTENDED PERIOD OF TIME
If the boiler is to be taken out of s ervice for an extended period of time (one year or mor e), the
following instructions must be followed.
Set ON/OFF switch on the front panel to the OFF position to shut down the boiler’s 1.
operating controls.
Disconnect AC power from the unit. 2.
Close the water supply and return valves to isolate boiler. 3.
Close external gas supply valve. 4.
Open relief valve to vent water pressure. 5.
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Page 90
Benchmark 1.5LN Low NOx Boiler
GF-120
OMM-0041 0E
CHAPTER 7
MAINTENANCE
Installation, Operation and Maintenance Manual
7.9 PLACING THE BOILER BACK IN SERVICE AFTER A PROLONGED SHUTDOWN
After a prolonged shutdown (one year or more), the following procedures must be followed:
1. Review installation requirements included in Chapter 2.
2. Inspect all piping and connections to the unit.
3. Inspect exhaust vent, air duct (if applicable).
4. Perform initial startup per Chapter 4.
5. Perform safety device testing and scheduled maintenance procedures per Chapters 6
and 7 of this manual.
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Page 91
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
CHAPTER 8
TROUBLESHOOTING
Installation, Operation and Maintenance Manual
CHAPTER 8. TROUBLESHO OTING GUIDE
8.1 INTRODUCTION
This troubleshooting guide is intended to aid service/maintenance personnel in isolating the
cause of a fault in a Benchmark 1.5 Boiler. The troubleshooting procedures contained herein
are presented in tabular form on the following pages. These tables are comprised of three
columns labeled: Fault Indication, Probable Cause and Corrective Action. The numbered items
in the Probable Cause and Corrective Action columns correspond to each other. For example,
Probable Cause No. 1 corresponds to Corrective Action No. 1, etc.
NOTE
The front panel of the C-More Control Box contains an RS232 port which
can be interfaced to a laptop computer or other suitable device. This
RS232 communication feature permits service personnel to view menu
items and data logs which can be useful in isolating faults. Refer to Chapter
9 of this manual for detailed RS232 communication set-up and procedures.
When a fault occurs in the Benchmark Boiler, proceed as follows to isolate and correct the fault:
Observe the fault messages displayed in the Control Box display. 1.
Refer to the Fault Indication column in Troubleshooting Table 8-1 which follows and 2.
locate the Fault that best describes the existing conditions.
Proceed to the Probable Cause column and start with the first item (1) listed for the Fault 3.
Indication.
Perform the checks and procedures listed in the Corrective Action column for the first 4.
Probable Cause candidate.
Continue checking each additional Probable Cause for the existing fault until the fault is 5.
corrected.
Paragraph 8.2 and Table 8-2 contain additional troubleshooting information which may 6.
apply when no fault message is displayed.
If the fault cannot be corrected using the information provided in the Troubleshooting 7.
Tables, contact your local AERCO Representative.
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Page 92
/12
CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
INDICATION
1. Blower stopped running due to thermal or
1. Check combustion blower for signs of excessive heat or high current
FAULT
PROBABLE CAUSES CORRECTIVE ACTION
Installation, Operation and Maintenance Manual
TABLE 8-1. BOILER TROUBLESHOOTING
TROUBLESHOOTING
current overload
2. Blocked Blower inlet or inlet ductwork
AIRFLOW FAULT
DURING IGNITION
3. Blocked Blower proof switch
4. Blocked blocked-air inlet switch
5. Defective Blower proof switch
6. Defective
blocked-air inlet switch
7. Loose temperature to AUX connection in I/O
Box
8. Defective temperature sensor
9. Loose wire connection between the 0-10V
signal from I/O box to the Blower Motor
input.
10. Defective I/O box
11. Wrong 0-10V output selection on the
control box
12. Defective Air-Fuel Valve potentiometer
drain that may trip thermal or current overload devices.
2. Inspect the inlet to the combustion blower including any ductwork
leading up to the combustion blower for signs of blockage.
3. Remove the Blower proof switch and inspect for signs of blockage,
clean or replace as necessary.
4. Remove the blocked-air inlet switch and inspect for signs of
blockage, clean or replace as necessary.
5. Measure the Blower proof switch for continuity with the combustion
blower running. If there is an erratic resistance reading or the
resistance reading is greater than zero ohms, replace the switch.
6. Measure the blocked-air inlet switch for continuity with the
combustion blower running. If there is an erratic resistance reading
or the resistance reading is greater than zero ohms, replace the
switch.
7. Check the actual inlet air temperature and measure voltage at AUX
input in the I/O Box. Verify that the voltage conforms to the values
shown in the tabular listing provided in Appendix C.
8. Refer to CORRECTIVE ACTION 7 and verify that the voltage
conforms to the values shown in Appendix C.
9. Check wire connection from I/O Box 0-10V signal to the Blower
Motor.
10. Measure voltage at the I/O box 0-10V output. A voltage of 8.2V
equates to a 100% open valve position.
11. Check the Analog Out option on the C-More Configurat ion Men u.
Valve Position 0-10V should be selected.
12. Check Air/Fuel Valve position at 0%, 50% and 100% open
positions. The positions on the VALVE POSITION bargraph should
match the dial readings on the Air/Fuel Valve dial.
Page 92 of 166 PR1:10/18
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Page 93
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
FAULT INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
applies for this fault
relay is okay,
ect the inlet to the combustion blower including any
ductwork leading up to the combustion blower for signs of
to the combustion blower including any
ductwork leading up to the combustion blower for signs of
Installation, Operation and Maintenance Manual
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
TROUBLESHOOTING
1. Blower not running or running too slow
2. Defective Air Flow Switch
3. Blocked Air flow Switch
AIRFLOW FAULT
DURING PURGE
AIRFLOW FAULT
DURING RUN
4. Blocked Blower inlet or inlet ductwork.
5. No voltage to switch from control box.
6. PROBABLE CAUSES from 3 to 16 for
AIRFLOW FAULT DURING IGNITION
1. Blower stopped running due to thermal
or current overload
2. Blocked Blower inlet or inlet ductwork
3. Blocked airflow switch
4. Defective airflow switch
1. Start the unit. If the blower does not r un check the blower solid
state relay for input and output voltage. If the
check the blower.
2. Start the unit. If the blower runs, check the airflow switch for
continuity. Replace the switch if there is no continuity.
3. Remove the air flow switch and inspect for signs of blockage,
clean or replace as necessary.
4. Insp
blockage.
5. Measure for 24 VAC during start sequenc e from eac h side of the
switch to ground. If 24VAC is not present refer to qualified
service personnel.
6. See CORRECTIVE ACTIONS f rom 3 to 16 for AIRFLOW FAULT
DURING IGNITION.
1. Check combustion blower for signs of excessive heat or high
current draw that may trip thermal or current overload devices.
2. Inspect the inlet
blockage.
3. Remove the airflow switch and inspect for signs of blockage,
clean or replace as necessary.
4. Measure the airflow switch for continuity with the combustion
blower running. If there is an erratic resistance reading or the
resistance reading is greater than zero ohms, replace the switch.
5. Combustion oscillations
6. PROBABLE CAUSES from 3 to 16 for
PR1: 10/18/12 Page 93 of 166
AIRFLOW FAULT DURING IGNITION
applies for this fault
5. Run unit to full fire. If the unit rumbles or runs rough, perform
combustion calibration.
6. See CORRECTIVE ACTIONS from 3 t o 16 f or AIRF L OW FAULT
DURING IGNITION.
Page 94
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CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
INDICATION
1. Check for a jumper properly installed across the delayed interlock
functional. (jumper ma y be temporar il y installed to test interlock)
(voltage or current).
Configuration Menu.
8. Closed RSI Gas Valve in RSI line.
8. Check position of RSI Gas Valve (Figure 8-1).
FAULT
Installation, Operation and Maintenance Manual
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
PROBABLE CAUSES CO RRECTIVE ACTION
TROUBLESHOOTING
1. Delayed Interlock Jumper not installed or
removed.
DELAYED
INTERLOCK OPEN
DIRECT DRIVE
SIGNAL FAULT
FLAME LOSS
DURING IGN
2. Device proving switch hooked to
interlocks is not closed
1. Direct drive signal is not present:
Not yet installed.
Wrong polarity.
Signal defective at source.
Broken or loose wiring.
2. Signal is not isolated (floating).
3. Control Box signal type selection
switches not set for correct signal type
1. Burner Ground Screw not installed or
loose.
2. Worn flame detector
3. No spark from Spark Plug
4. Defective Ignition Transformer
5. Defective Ignition/Stepper (IGST) Board
6. Defective SSOV
7. RSI Regulator not properly adjusted.
terminals in the I/O box.
2. If there are 2 external wires on these terminals, check to see if an
end switch for a device such as a pump, louver, etc. is tied these
interlocks. Ensure that the device and or its end switch are
1. Check I/O Box to ensure signal is hooked up.
Hook up if not installed.
If installed, check polarity.
Measure signal level.
Check continuity of wiring between source and boiler.
2. Check signal at source to ensure it is isolated.
3. Check DIP switch on PMC board to ensure it is set correctly for the
type of signal being sent. Check control signal type set in
1. Inspect and install/retighten Burner Ground Screw.
2. Remove and inspect the flame detector for signs of wear. Replace
if necessary.
3. Close the internal gas valve in the boiler. Install and arc a spark
ignitor outside the unit.
4. If there is no spark, check for 120VAC at the primary side to the
ignition transformer during the ignition cycle.
5. If 120VAC is not present, the IGST Board in the Control Box may
be defective. Refer fault to qualified service personnel.
6. While externally arcing the spark ignitor, observe the open/close
indicator in the Safety Shut-Off Valve to ensure it is opening. If the
valve does not open, check for 120VAC at the valves input
terminals. If 120VAC is not present, the IGST board in the Control
Box may be defective. Refer fault to qualified service personnel.
7. Refer to Chapter 7, paragraph 7.4 and check the RSI Regulator
calibration. The RSI regulator output should be between 3.0” W.C.
and 5.0” W.C.
Page 94 of 166 PR1:10/18
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Page 95
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
FAULT INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
2030:
1. Measure the actual exhaust temperature and continuity of the
Installation, Operation and Maintenance Manual
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
TROUBLESHOOTING
FLAME LOSS
DURING IGN
(continued)
FLAME LOSS
DURING RUN
HEAT DEMAND
FAILURE
9. Unstable gas pressure.
10. Carbon or other debris on Burner.
11. Staged ignit ion sole no id val ves
don’t open.
12. Clogged staged ignition piece.
1. Worn Flame Detector or cracked
ceramic.
2. Defective Regulator.
3. Poor combustion calibration.
4. Debris on burner.
5. Blocked condensate drain.
1. The Heat Demand Relays on the
Ignition/Stepper board failed to
activate when commanded.
2. Relay is activated when not in
Demand
9. Refer to “Gas Pressure Requirements” section of GFBMK Gas Supply Design Guide.
10. Remove the burner and inspect for any carbon or debris.
Clean and reinstall.
11. When boiler goes to ignit ion, listen to the sol enoid valves for a
clicking sound to ensure they are opening.
12. Remove and inspect staged ignition piece for blockage.
1. Remove and inspect the Flame Detector for signs of wear or
cracked ceramic. Replace if necessary.
2. Check gas pressure readings using a gauge or manometer into
and out of the Air/Fuel Valve to ensure that the gas pressure
into and out of the valve is correct.
3. Check combustion calibration. Adjust as necessary.
4. Remove the burner and inspect for any carbon or debris. Clean
and reinstall.
5. Remove blockage in condensate drain.
1. Press CLEAR button and res tart the unit. If the fault persists ,
replace Ignition/Stepper (IGST) Board.
2. Defective relay. Replace IGST Board.
1. Defective exhaust sensor.
HIGH EXHAUST
TEMPERATURE
2. Carboned heat exchanger due to
incorrect combustion calibration
PR1: 10/18/12 Page 95 of 166
exhaust sensor. If the exhaust temperature is less than 475
F and the exhaust sensor shows continuity replace the
sensor.
2. If exhaust temperature is greater than 500o F, check
combustion calibration. Calibrate or repair as necessary.
o
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CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
INDICATION
what the boilers can respond to.
2. Temp HI Limit setting is too low.
2. Check Temp HI Limit setting.
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
FAULT
Installation, Operation and Maintenance Manual
PROBABLE CAUSES CORRECTIVE ACTION
TROUBLESHOOTING
HIGH GAS
PRESSURE
HIGH WATER
TEMP
SWITCH OPEN
1. Incorrect supply gas pressure.
2. Defective SSOV Actuator.
3. Defective High Gas Pressure Switch
4. Gas pressure snubber not installed.
1. Faulty Water temperature switch.
2. Incorrect PID settings.
3. Faulty shell temperature sensor.
4. Unit in Manual mode
5. Unit setpoint is greater than Over Temperature
Switch setpoint.
6. Boiler Management System PID or other
settings not correctly setup.
7. No interlock to boiler or BMS to disable
boiler(s) in event that system pumps have
failed.
8. System flow rate changes are occurring faster
than boilers can respond.
1. Check to ensure gas pressure at inlet of SSOV is 14” W.C.
maximum.
2. If gas supply pressure downstream of SSOV Actuator cannot be
lowered, to 1.5” W.C. using the gas pressure adjustment screw
(see para. 4.3, step 10), the SSOV Actuator may be defective.
3. Remove the leads from the high gas pressure switch and measure
continuity across the common and normally closed terminals with
the unit not firing. Replace the switch if it does not show continuity.
4. See Figure 8-1. Ensure that the gas pressure snubber is installed
at the high gas pressure switch.
1. Test the temperature switch to insure it trips at its actual water
temperature setting.
2. Check PID settings against Menu Default settings in the Appendix.
If the settings have been changed, record the current readings then
reset them to the default values.
3. Using the resistance charts in the Appendix C, Measure the
resistance of Shell sensor and BTU sensor at a known water
temperature.
4. If unit is in Manual Mode switch to Auto Mode.
5. Check setpoint of unit and setpoint of Temperature Switch; Ensure
that the temperature switch is set higher than the unit’s setpoint.
6. Check the BMS for changes to PID default values, correct as
necessary.
7. If system pump is controlled by Energy Management System other
than BMS or pumps are individually controlled by boiler, check to
see if there are flow switches interlocked to the BMS or boiler.
8. If the system is a variable flow system, monitor system flow
changes to ensure that the rate of flow change is not faster than
HIGH WATER
TEMPERATURE
Page 96 of 166 PR1:10/18
1. See HIGH WATER TEMPERATURE SWI TCH OPEN.
1. See HIGH WATER TEMPERATURE SWITCH OPEN.
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AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
FAULT INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
/Fuel Valve should rotate to the purge
ignition position, check the Air/Fuel Valve calibration. If
Installation, Operation and Maintenance Manual
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
TROUBLESHOOTING
IGN BOARD
COMM FAULT
IGN SWTCH CLOSED
DURING PURGE
IGN SWTCH OPEN
DURING IGNITION
1. Communication fault has occurred
between the PMC board and
Ignition/Stepper (IGST) board
1. Air/Fuel Valve not rotating
2. Defective or shorted switch
3. Switch wired incorrectly
4. Defective Power Supply Board or
fuse
5. Defective IGST Board
1. Air/Fuel Valve not rotating to
ignition position.
2. Defective ignition switch
3. Defective Power Supply Board or
fuse
4. Defective IGST Board
1. Press CLEAR button and restart unit. If fault persists, contact
qualified Service Personnel.
1. Start the unit. The Air/Fuel Valve should rotate to the purge
(open) position. If the valve does not rotate at all or does not
rotate fully open, check the Air/Fuel Valve calibration. If
calibration is okay, the problem may be in the Air-Fuel Valve or
the Control Box. Refer to qualified service personnel
2. . If the Air/Fuel Valve does rotate to purge, check the ignition
switch for continuity between the N.O. and COM terminals. If the
switch shows continuity when not in contact with the cam replace
the switch.
3. Check to ensure that the switch is wired correctly (correct wire
numbers on the normally open terminals). If the switch is wired
correctly, replace the switch
4. Check DS1 & DS2 LEDs on Power Supply Board. If they are not
steady ON, replace Power Supply Board.
5. Check “Heartbeat” LED DS1 and verify it is blinking ON & OFF
every second. If not, replace IGST Board.
1. Start the unit. The Air
(open) position, then back to ignition position (towards closed)
during the ignition c ycle. If the valve does not rotate b ack to the
calibration is ok ay, the problem may be in the A ir/Fuel Valve or
the Control Box. Refer fault to qualified service personnel.
2. If the Air/Fuel Valve does rotate to the ignit io n p os ition , c hec k the
ignition position switch for contin uity between the N.O. and COM
terminals when in contact with the cam.
3. Check DS1 & DS2 LEDs on Power Supply Board. If they are not
steady ON, replace Power Supply Board.
4. Check “Heartbeat” LED DS1 and verify it is blinking ON & OFF
every second. If not, replace IGST Board.
PR1: 10/18/12 Page 97 of 166
Page 98
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CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
INDICATION
1. Interlock jumper not installed or
PHASE
wiring.
continuity.
FAULT
Boiler not seeing information from
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
FAULT
PROBABLE CAUSES CORRECTIVE ACTION
Installation, Operation and Maintenance Manual
TROUBLESHOOTING
INTERLOCK
OPEN
LINE
VOLTAGE
OUT OF
LOW GAS
PRESSURE
LOW WATER
LEVEL
removed
2. Energy Management System does not
have boiler enabled.
3. Device proving switch hooked to
interlocks is not closed.
1. Line and Neutral switched in AC
Power Box.
2. Incorrect power supply transformer
1. Incorrect supply gas pressure.
2. Defective Low Pressure Gas Switch
1. Insufficient water level in system
2. Defective water level circuitry.
3. Defective water level probe.
1. Check for a jumper properly installed across the interlock terminals in the
I/O box
2. If there are two external wires on these terminals check any Energy
Management system to see if they have the units disabled (a jumper may
be temporarily installed to see if the interlock circuit is functioning).
3. Check that proving switch for any device hooked to the interlock circuit is
closing and that the device is operational.
1. Check hot and neutral in AC Power Box to ensure they are not reversed
2. Check transformer wiring, in AC Power Box, against the power box
transformer wiring diagram to ensure it is wired correctly
1. Measure gas pressure upstream of the SSOV Actuator(s) with the unit
firing. For FM gas trains, ensure it is between 4.0” W.C. and 14” W.C..
For IRI gas trains, ensure it is between 4.2" W.C. and 14” W.C. (see para.
2.7.1).
2. Measure gas pressure at the low gas pressure switch. If it is greater than
2.6” W.C., measure continuity across the switch and replace if necessary.
1. Check system for sufficient water level.
2. Test water level circuitry using the Control Box front panel LOW WATER
TEST and RESET buttons. Replace water level circuitry if it does not
respond.
3. Check continuity of probe end to the shell, change probe if there is no
MODBUS
COMM
PRG SWTCH
CLOSED
DURING
IGNITION
Page 98 of 166 PR1:10/18
1.
Modbus network
1. A/F Valve rotated open to purge and
did not rotate to ignition position.
1. Check network connections. If fault persists, contact qualified Service
Personnel.
1. Start the unit. The Air/Fuel Valve should rotate to the purge (open)
position, then back to ignition pos itio n (towards close d) dur ing the i gnition
cycle. If the valve d oes not rotate bac k to the ignit ion position, chec k the
Air/Fuel Valve cal ibration. If calibration is ok ay, the problem may be in
the Air/Fuel Valve or the Control Box. Refer fault to qualified service
personnel.
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CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
FAULT INDICATION
PROBABLE CAUSES
CORRECTIVE ACTION
for continuity between the N.O. and COM
every second. If not, replace IGST Board.
nuity does not
3. Incorrect Sensor.
Check resistance of sensor to determine if it is within
3. Ensure that the correct sensor is installed.
current).
Configuration Menu.
Installation, Operation and Maintenance Manual
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
TROUBLESHOOTING
PRG SWTCH
CLOSED
DURING
IGNITION
(continued)
PRG SWTCH OPEN
DURING PURGE
OUTDOOR TEMP
SENSOR FAULT
2. Defective or shorted switch.
3. Switch wired incorrectly.
4. Defective Power Supply Board or fuse
5. Defective IGST Board
1. Defective purge switch.
2. No voltage present at switch.
3. Switch wired incorrectly.
4. Defective Power Supply Board or fuse
5. Defective IGST Board
1. Loose or broken wiring.
2. Defective Sensor.
2. If the Air/Fuel Valve does rotate to the ignition position, check
the purge switch
terminals. If the switch shows continuity when not in contact
with the cam, check to ensure that the s witch is wired correctly
(correct wire numbers on the normally open terminals).
3. If the switch is wired correctly, replace the switch.
4. Check DS1 & DS2 LEDs o n Po wer Su ppl y Board. If the y are not
steady ON, replace Power Supply Board.
5. Check “Heartbeat” LED DS1 and verify it is blinking ON & OFF
1. If the air-fuel valve does rotate, check the purge switch for
continuity when closing. Replace switch if conti
exist.
2. Measure for 24 VAC from each side of the s witch to ground. If
24VAC is not present, refer fault to qualified service personnel.
3. Check to ensure that the switch is wired c orrectly (correct wire
numbers on the normally open terminals).
4. Check DS1 & DS2 LEDs o n Po wer Su ppl y Board. If the y are not
steady ON, replace Power Supply Board.
5. Check “Heartbeat” LED DS1 and verify it is blinking ON & OFF
every second. If not, replace IGST Board.
1. Inspect Outdoor Temperature sensor for loose or broken wiring.
2.
specification.
1. Remote setpoint signal not present:
Not yet installed.
Wrong polarity.
REMOTE SETPT
SIGNAL FAULT
PR1: 10/18/12 Page 99 of 166
Signal defective at source.
Broken or loose wiring.
2. Signal is not isolated (floating) if 4 to 20 mA.
3. Control Box signal type selection switches
not set for correct signal type (voltage or
1. Check I/O Box to ensure signal is hooked up.
Hook up if not installed.
If installed, check polarity.
Measure signal level.
Check continuity of wiring between source and boiler.
2. Check signal at source to ensure it is isolated.
3. Check DIP switch on PMC board to ensure it is set correctly for
the type of signal being sent. Check control signal type set in
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CHAPTER 8
GF-120
OMM-0041 0E
Benchmark 1.5LN Low NOx Boiler
INDICATION
1. SSOV not fully closed.
2. Replace Flame Detector.
PURGE
4. Incorrectly wired switch.
4. Ensure that the SSOV Proof of Closure switch is correctly wired.
Stepper Feedback Calibration (GF-112, para. 6.2.1).
FAULT
RESIDUAL
FLAME
PROBABLE CAUSES CORRECTIVE ACTION
2. Defective Flame Detector
Installation, Operation and Maintenance Manual
TABLE 8-1. BOILER TROUBLESHOOTING (Continued)
1. Check open/close indicator window of Safety Shut-Off Valve (SSOV) and ensure
that the SSOV is fully closed. If not fully closed, replace the valve and or actuator.
Close gas shut-off valve downstream of SSOV. Install a manometer or gauge in a
gas test port between the SSOV and the gas shut off valve. If a gas pressure
reading is observed replace the SSOV valve and or actuator.2.
TROUBLESHOOTING
SSOV FAULT
DURING
SSOV FAULT
DURING RUN
SSOV RELAY
FAILURE
SSOV
SWITCH
OPEN
STEPPER
MOTOR
FAILURE
See SSOV SWIT CH OPEN
1. SSOV switch closed for 15
seconds during run.
1. SSOV relay failed on board.
2. Floating Neutral.
3. Hot and Neutral reversed at SSOV.
1. Actuator not allowing for full closure
of gas valve
2. SSOV powered when it should not
be
3. Defective Switch or Actuator
1. Air/Fuel Valve out of calibration.
1. Replace or adjust microswitch in SSOV actuator. If fault persists, replace
actuator.
1. Press CLEAR button and restart unit. If fault persists, replace Ignition/Stepper
(IGST) Board.
2. The Neutral and Earth Ground are not connected at the source and therefore
there is a voltage measured between the two. Normally this measurement should
be near zero or no more than a few millivolts.
3. Check SSOV power wiring.
1. Observe operation of the Safety Shut-Off Valve (SSOV) through indicator on the
Valve actuator and ensure that the valve is fully and not partially closing.
2. If the SSOV never closes, it may be powered continuously. Close the gas supply
and remove power from the unit. Refer fault to qualified service personnel.
3. Remove the electrical cover from the SSOV and check switch continuity. If the
switch does not show continuity with the gas valve closed, either adjust or replace
the switch or actuator.
1. Refer to GF-112 and perform Stepper Test (para. 6.3.5) to ensure stepper motor
rotates properly between the 0% (fully closed) and 100% (fully open) positions.
Verify that the VALV E PO S I T I ON bargraph and the dial on the Air/Fuel Valve track
each other to indicate proper operation. If operation is not correct, perform the
Page 100 of 166 PR1:10/18
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
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