Aerco KC Series Installation, Operation & Maintenance Instructions Manual page 50

20. Restore electrical power to the unit and
restart the unit.
21. If the safety shutoff valve still does not open,
proceed to section 7.7.8.
22. Be sure to return the safety shutoff valve to
its original position and replace all cover
plates.
7.5.4 SPARK IGNITOR
1. Disconnect electrical power to the unit.
2. Remove the spark ignitor as per
Maintenance Section 6.3 of this manual.
3. Inspect the ignitor for signs of erosion.
4. Replace the ignitor if eroded.
Check for carbon buildup on the ignitor.
5. If there is carbon build-up on the ignitor, the
combustion calibration settings must be
checked as per Section 4. If the spark
ignitor is not eroded, it may be cleaned and
reused.
7.5.5 FLAME DETECTOR
1. Disconnect electrical power to the unit.
2. Remove the flame detector as per
Maintenance Section 6.3.
3. Check the detector for signs of erosion or
carbon buildup.
4. If the flame detector is eroded, replace it.
Otherwise, clean it using emery cloth.
5. Carbon buildup on the flame detector
indicates that unit may require combustion
calibration.
6. Check the combustion calibration settings as
per Start-Up Sections 4.3 and 4.4.
7.5.6 IGNITION CIRCUIT
1. Disconnect electrical power to the unit.
2. Close the manual-leak detection valve,
located between the safety shutoff valve and
the differential pressure regulator, on the
unit's gas manifold.
3. Using either a spare ignitor, connect the
ignition cable directly to the ignitor.
4. Ground the ignitor to the frame of the unit.
5. Restore electrical power to the unit.
TROUBLESHOOTING
6. Start the unit.
7. At ignition, an arc should be observed. It
should last for approximately 15 seconds.
8. If there is no arc, disconnect electrical power
to the unit.
WARNING!
ELECTRIC SHOCK HAZARD. THE
SECONDARY OF THE IGNITION
TRANSFORMER HAS A POTENTIAL OF
6000 VOLTS. DO NOT HOLD OR TOUCH
ANY IGNITION CIRCUIT COMPONENTS
WHILE TESTING.
9. Remove the ignition cable and check it for
continuity or loose connections.
10. Replace the cable if there is no continuity. If
there is a loose connection, replace or repair
the cable as necessary.
11. If the ignition cable is okay, remove the
ignition transformer cover plate.
12. Referring to system schematic 161412 in
Appendix F, locate wires #12 and #29.
13. Connect an AC voltmeter across wires #12
and #29.
14. Restore electrical power to the unit and start
the unit.
15. At the ignition cycle check for 120 VAC
across wires #12 and #29.
16. If 120 VAC is observed across wires #12
and #29, replace the ignition transformer.
17. If 120 VAC is not observed on the AC
voltmeter during the Ignition cycle,
disconnect electrical power to the unit.
18. Disconnect the 9-pin connector from the
control panel, and wires #12 and #29 from
the ignition transformer.
19. Remove the cover plate from the AC wiring
box.
20. Referring to system schematic 161412 in the
Appendix, check wires #12 and #29 for
continuity.
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