T M 1 0 - 4 6 1 0 - 2 3 2 - 1 2
Table 4-2. Unit Troubleshooting Guide (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
(a) Set it to heat position.
(b) Notify direct support maintenance.
3. Electric heater heats up but fan does not work.
Notify direct support maintenance.
4. Electric heater circuit breaker trips whenever the heater is started (Reference Schematic Diagram FO-1, sheet
5, schematic lines 512-515).
Replace heater (para. 4-77).
5. Electric heater circuit breaker will not reset (Reference Schematic Diagram FO-1, sheet 5, schematic lines
Check for a short circuit.
1. Raw water pump heat lamp does not work (Reference Schematic Diagram FO-1, sheet 5, schematic lines
1105-1109).
Step 1.
Step 2.
Step 3.
Step 4.
NOTE
Circuit breaker 13 is a ground fault breaker. High humidity or moisture around de-
vices controlled by this breaker may occasionally cause troubles. Check that atmos-
pheric moisture is not causing the tripping by drying out anything controlled by this
breaker, including wire connections.
Check for voltage (110-120 VAC) across J55A and J55B (Reference Interconnection Diagram FO-2,
sheet 16) on the outside of the van. (This heater only works when the pump is shut down and the pump
heat switch is on.)
If voltage is not present, go to step 3.
Shut down the ROWPU. Shutdown the generator. Refer to the electrical schematics and interconnect
diagrams in Appendix l. Check the cable to the heat lamp, point-to-point, for continuity or shorts.
(a) If the cables are defective, replace the cable (para. 4-89).
(b) If the heat lamp is defective, replace the heat Iamp (para. 4-89).
Remove connector P18 (Reference Interconnection Diagram FO-2, sheet 15) from the control panel
and check for voltage across J18D and J18E (Reference Interconnection Diagram FO-2, sheet 9).
If voltage is not present, notify direct support maintenance.
Shut down the ROWPU. Shutdown the generator. Refer to the electrical schematics and interconnect
diagrams in Appendix l. Check for shorts and continuity, point-to-point, from P18D and E to J56A
and B, (Reference Interconnection Diagram FO-2, sheet 16) respectively. Open the raw water pump
outside electrical panel. Check MOV Nos. 14 and 15 (Reference Interconnection Diagram FO-2,
sheet 16) for physical damage or signs of shorting. Remove wire Nos. 443 and 448 from the MOV
terminals. Use a multimeter and check for continuity from the terminals which the wires were on to
ground.
(a) If a cable or connector is defective, replace the cable assembly (para. 4-27).
(b) Repair any loose or damaged wires in the external electrical panel (para. 4-34).
(c) Replace any damaged wiring harness in the external electrical panel (para. 4-34).
(d) Replace any MOV which is physically damaged or shows continuity to ground from the power
terminal (para. 4-34).
2. Distribution pump heat lamp does not work (Reference Schematic Diagram FO-1, sheet 11,
1110-1114).
NOTE
Circuit breaker 14 is a ground fault breaker. High humidity or moisture around de-
vices controlled by this breaker may occasionally cause troubles. Check that atmos-
pheric moisture is not causing the tripping by drying out anything controlled by this
breaker, including wire connections.
schematic lines
4-40
Change 1
512-515).
