Carrier VECTOR 6500 Operation & Service Manual page 182

Alarm
Steps
NO.
76 CONDENSER MOTOR OVERHEATED
•
TRIGGER–ON: One or both of the condenser fan motor Internal Protectors (IP-CDM1 AND 2) cir-
cuit is open.
•
UNIT CONTROL:
•
RESET CONDITION: Auto Reset when motor overload input is within limits, or change to engine
Operation, or alarm may be manually reset via keypad or by turning the unit off, then back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, the active
alarm should clear itself (see reset condition above). Operate the unit through the appropriate modes to see if
any active alarm occurs. Continue with the steps below as necessary.
1 Check Condenser Fan Blades for Free Operation
Visually inspect condenser fan
blades for any foreign material or
damage or anything that will prevent
the blade and motor from turning
freely
2 Check For 12 VDC At 4MP2
a. If 12VDC.
b. If no power (0VDC.)
3 Check IPC circuit
a. Check MPQC9.
b. Use Component Test Mode to ener-
gize CDCON circuit. (Refer to Sec-
tion 5.2.2.)
c. Unplug the connector to condenser
fan motor 1 (CDM1) and check
voltage on pins 4-5 in the engine
harness connector.
d. Test continuity through CDM1 IP at
pins 4-5 in the fan motor harness
connector.
e. Test continuity through IPC.
f. Test IP circuit from condenser fan
motor wires to microprocessor.
4 Check Condenser Fan Motor Contactor
a. Inspect the wire connections to
the contactor. (See wiring schem-
atic Section 10.)
b. Check tightness of the contactor
wire connections.
5 Perform Pretrip
Clear Active Alarm list, then run Pre-
trip & check for any new alarms.
Additional steps on the next page.
Alarm/Cause
Engine Operation: engine and unit shutdown and alarm.
Standby Operation: refrigeration system shutdown and alarm with PSCON
still energized.
7−49
Corrective Action
Fan blade must be in good condition.
No sticks or other material obstructing it's movement
No ice build-up preventing blade rotation.
Alarm should have cleared itself.
Continue with step 2 below.
There should be 12 VDC from MPQC9 to Ground.
FET 1 will be on.
12 VDC between pin 4 and pin 5 indicates the open
circuit is in the IP for CDM1.
Should be 0 Ohms. If condenser fan motor 1 is
extremely warm, allow it to cool off, then recheck IP
continuity.
Should be 0 Ohms. If either condenser fan motor is
extremely warm, allow it to cool off, then recheck IPC
continuity.
12 VDC at 4MP2.
No signs of overheating of the contactor. Wiring is
routed correctly to the contactor.
Tighten with screwdriver and check for discoloration
of wires.
Any active alarms must be corrected and cleared be-
fore proceeding.
62-11389