Aerco KC Series Installation, Operation & Maintenance Instructions Manual page 48

10. Place the entire length of the sensors in a
water bath of known temperature. Measure
the resistance of the probe, and determine
the corresponding temperature from the
temperature sensor chart. If there is a
significant discrepancy, greater than 10°F
then replace the sensor.
11. Disconnect the 6 pin connector from the
control panel.
12. Referring to system schematic 161412 in
Appendix F, locate wires #1, #2, #3, #4 and
#5.
13. Check all wires for continuity and all
connectors for proper pin insertion and/or
worn pins. Repair as necessary.
14. If the sensors wiring and connectors are
okay. Place a 1000Ω ± 1% accuracy
resistor across the pins in the plugs that the
sensors were removed from.
NOTE:
The resistors must be placed across the
pins simultaneously to get accurate
readings.
NOTE:
If the sensors are removed and power is
applied to the unit the message bAd.InP will
be displayed on the temperature control.
To clear this error press and hold the
INDEX and ENTER buttons simultaneously.
15. Reapply power to the unit.
16. Check the temperature control displays tout
in the primary menu and FFt in the
secondary menu. They should both read
70°F ± 10°F.
17. Place a 1.3 KΩ ± 1% resistor across the pins
in the plugs that the sensors were removed
from.
18. The temperature controller displays tout in
the Primary menu and FFt in the Secondary
menu should read 196° F ±10° F.
19. If the temperatures displayed are not within
tolerance the control should be replaced.
NOTE
If the display reads UFL or OFL or bAd InP,
this is an indication that the sensor wires
:
43
TROUBLESHOOTING
are shorted or in an open circuit condition,
which may indicate a wiring problem.
20. If the sensors wiring and connectors are
okay, reinstall the sensors.\
21. Reconnect the connectors to the sensors
and control panel, ensuring that they lock
firmly into place.
22. Refill the unit as per Section 2.8.1.
23. Restore electrical power to the unit.
7.5 LOCKOUT RUN FLAME
A LOCKOUT RUN FLAME message indicates
that the flame signal was lost after the unit
proved flame and was released to modulate. A
FLAME FAULT DURING IGN TRIAL message
indicates that flame was not recognized during
the ignition trial period.
7.5.1 Flame Fault While Firing
7.5.2 Flame Fault During Ignition Cycle
7.5.3 Safety Shut Off Valve
7.5.4 Spark Ignitor
7.5.5 Flame Detector
7.5.6 Ignition Circuit
7.5.7 Air Fuel Valve Ignition Position
witch
7.5.8 Flame Detector Voltage
7.5.9 Residual Flame
Recommended Troubleshooting Equipment
Digital or Analog Voltmeter
Combustion Analyzer
and 16" Manometers
7.5.1 FLAME FAULT WHILE FIRING
1. Install a DC voltmeter in the flame test jacks
located on the front of the combustion
safeguard. Start the unit in manual mode
2. Once flame is established, a steady reading
of approximately 5 VDC should be observed.
3. While in manual mode, fire the unit at
various firing rates (i.e., 16%, 30%, 50%,
100% etc.)
4. If flame signal is erratic at any time during
the test, combustion calibrate the unit as per
Section 4.this manual.
5. If combustion calibration is okay, remove the
burner and inspect it for debris that may
have fallen on it.
7.5.2 FLAME FAULT DURING IGNITION
TRIAL
1. Check that all gas supply valves are open