Carrier VECTOR 6500 Operation & Service Manual page 181

Alarm
Steps
NO.
75 COMP MOTOR OVERLOAD
•
TRIGGER–ON: Compressor Motor Internal Protector (IPC) circuit 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 For Alarm13 (A13 or I13 = High Pressure)
Alarm 13 will always cause this
alarm to activate, even when there
are no problems with this circuit.
2 Check For 12 VDC At 4MP1
a. If 12VDC.
b. If no power (0VDC.)
3 Check IPC circuit
a. Use Component Test Mode to ener-
gize CCON circuit (Refer to Section
5.2.2.)
b. Check IPC harness to microproces-
sor.
c. Check SP15.
d. Test continuity through IPC.
e. Test IP circuit from compressor mo-
tor to microprocessor.
4 Check Compressor Motor Contactor
a. Inspect the wire connections to the
contactor. (See wiring schematic
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.
6 Check Compressor Motor Operation
Turn the unit ON in Engine or Stand-
by Operation.
62-11389
Alarm/Cause
Engine Operation: engine and unit shutdown and alarm.
Standby Operation: refrigeration system shutdown and alarm with PSCON
still energized.
7−48
Corrective Action
Review steps for Alarm 13 and correct if necessary.
Alarm should have cleared itself.
Continue with step 3.
FET 2 will be on.
12 VDC on terminals 8 & 9 at the compressor (white
wires.)
There should be 12 VDC from HP1 to SP15 to IPC.
Should be 0 Ohms. If compressor body is extremely
warm, allow it to cool off, then recheck IPC continuity.
12 VDC at 4MP1.
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.
Check voltage and current on each phase (voltage
and amperage must be within allowable range (Refer
to Section 2.11 for correct electrical values.)