MAINTENANCE
7-3
7.3 FLAME DETECTOR
The flame detector, part no. 66034, is located in
the body of the burner (see Figure 7-1). The
flame detector may be HOT. Allow the unit to
cool sufficiently before removing the flame
detector.
To inspect or replace the flame detector:
1. Set the ON/OFF switch on the control panel,
to the OFF position. Disconnect AC power
from the unit.
2. Remove the top panels from the unit.
3. Disconnect the lead wire from the flame
detector.
4. Remove the two (2) screws securing the
flame detector to the burner housing (Figure
7-1). The flame detector is secured to the
burner housing with one (1) #10-32 screw
and one (1) #8-32 screw.
5. Remove the flame detector and gasket from
the burner housing.
6. Inspect the detector thoroughly. If eroded,
the detector should be replaced. Otherwise
clean the detector with a fine emery cloth.
7. Reinstall the flame detector and flame
detector gasket.
8. Reconnect the flame detector lead wire.
9. Reinstall the top and side panels on the unit.
7.4 COMBUSTION CALIBRATION
Combustion settings must be checked at the
intervals shown in Table 7-1 as part of the
maintenance requirements. Refer to Chapter 4
for combustion calibration instructions.
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 6-Safety Device Testing Procedures.
7.6 BURNER ASSEMBLY INSPECTION
The burner assembly is located at the top front
of the unit. The burner assembly may be hot.
Allow the unit to cool sufficiently before removing
the burner assembly.
The following
replacement parts will be
necessary for reassembly following inspection:
Part No.
Description
81030
Burner Gaskets (Qty= 2)
81019
Burner Housing Gasket
81048
Flame Detector Gasket
To inspect or replace the burner assembly:
1. Set the
ON/OFF
switch on the control panel,
to the
OFF
position. Disconnect AC power
from the unit and turn off the gas supply.
2. Remove the side and top panels from the
unit.
3. Disconnect the lead wire from the flame
detector (see Figure 7-1).
4. Remove the two (2) screws securing the
flame detector to the burner housing. the
flame detector is secured to the burner
housing with one (1) #10-32 screw and one
(1) #8-32 screw.
5. Remove the flame detector and gasket from
the burner housing.
6. Disconnect the cable from the ignitor-injector.
7. Using a 7/16” open-end wrench, disconnect
the compression nut securing the gas
injector tube of the ignitor-injector to the
elbow of the staged ignition assembly.
Disconnect the staged ignition assembly
from the ignitor- injector.
8. Loosen and remove the ignitor-injector from
the burner plate using a 1" wrench.
9. Disconnect the burner housing from the
blower by removing the six (6) 1/4-20
screws using a 3/8” wrench.
10. Remove the eight (8) 3/8-16 nuts from the
burner flange (Figure 7-3) using a 9/16”
wrench.
NOTE
The burner housing is heavy, weighing
approximately 25 pounds.
11. Refer to the exploded view in Figure 7-4.
Remove the burner housing from burner
flange by pulling straight up.
12 .Remove the grounding screw.
13. Remove the burner by pulling straight up.
14. Remove and replace the burner gaskets.
Summary of Contents for Benchmark 3.0LN Series
Page 6: ...iv ...
Page 8: ...B ...
Page 42: ...INITIAL START UP 4 8 ...
Page 80: ...A 6 ...
Page 84: ...B 4 ...
Page 86: ...C 2 APPENDIX C ...
Page 93: ...APPENDIX F APPENDIX F F 1 ...
Page 94: ...APPENDIX F F 2 ...
Page 95: ...APPENDIX F F 3 ...
Page 96: ...APPENDIX F F 4 ...
Page 97: ...APPENDIX F F 5 ...
Page 98: ...APPENDIX F F 6 ...
Page 99: ...APPENDIX F F 7 66034 ...
Page 100: ...APPENDIX F F 8 ...
Page 101: ...APPENDIX F F 9 ...
Page 102: ...APPENDIX F F 10 ...
Page 103: ...APPENDIX F F 11 ...
Page 104: ...APPENDIX F F 12 ...
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Page 107: ...APPENDIX G APPENDIX G G 1 ...
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Page 109: ...APPENDIX G G 3 ...
Page 110: ...APPENDIX G G 4 ...
Page 111: ...APPENDIX G G 5 ...
Page 112: ...APPENDIX G G 6 ...
Page 113: ...APPENDIX H APPENDIX H H 1 ...
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Page 122: ...APPENDIX I I 2 ...
Page 126: ...NOTES ...
