Defrost Not Complete - Carrier VECTOR 1550 Series Operation & Service Manual

Alarm
Steps
NO.
54

DEFROST NOT COMPLETE


TRIGGER-ON: Defrost cycle did not complete within 45 minutes

UNIT CONTROL: Engine and standby operation: alarm only. While this alarm is active, the Defrost
Timer will be set to initiate a defrost cycle 90 minutes (1.5 hours) of unit running time after the alarm
comes on.

RESET CONDITION: Auto Reset when defrost cycle is started again, 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 (refer to 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 Heat & Sensor Alarms
a. Check the Alarm List for alarms
91, 92 &/or 124
1 Perform Pretrip Check
a. Clear Active Alarm list, then run
Pretrip & check for any new
alarms.
Check For Defective Defrost Sensor Location/Correct Installation
2
a. Has sensor fallen from location?
3 Check Evaporator Fan Contactor
a. Check that contactor is not ener-
gized and that the contacts are not
stuck closed when in defrost.
4 Check Evaporator Heater Current Draw
a. Check Heater amp draw for
HTCON1
b. Check Heater amp draw for
HTCON2
62-61753-21
ALARM / CAUSE CORRECTIVE ACTION
Alarm conditions must be corrected and the alarm
cleared to continue.
Any active alarms must be corrected and cleared be-
fore proceeding.
Must be corrected to continue.
Must de-energize evaporator fan during defrost.
Verify that all three actual amperage readings for each
component are within 10% of each other, and are with-
in the values shown in Section 2.11.
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