36
ComPac 9/04-12
1. Dirty filter or reduced airflow
2. Low refrigerant.
3. Component failure.
4. Unit undersized for job.
B. Unit runs for long periods or
continuously; cooling is
insufficient.
1. Check air filter(s). Check blower
operation. Remove airflow
restriction.
2. Check for proper charge and
possible refrigerant leak.
3. Check internal components,
especially compressor for proper
operation.
4. Add additional units for greater
capacity.
1. Check blower assembly for
proper operation. Look for
airflow restrictions, e.g.. the air
filter. Check blower motor and
condenser fan.
2. Check for blockage or restriction,
especially filter drier and
capillary tube assembly.
3. Evacuate and recharge to factory
specifications.
4. Check limit cutout pressures.
Control is set to actuate at approxi-
mately 35 PSIG (low pressure) and
400 PSIG (high pressure).
1. Note electrical requirements in
Chapter 2 and correct as necessary.
2. Check field wiring for errors.
3. Check wiring in unit. See wiring
and schematic diagrams. Test
components (especially the
compressor) for shorts.
4. Note voltage range limitations
specific to the compressor
troubleshooting section.
1. Loss or restriction of airflow.
2. Restriction in refrigerant circuit.
3. Refrigerant overcharge
(following field service)
4. Defective pressure control.
1. Inadequate circuit ampacity.
2. Short, loose, or improper
connection in field wiring.
3. Internal short circuit. Loose or
improper connection(s) in unit.
4. Excessively high or low supply
voltage or phase loss (3ø only).
C. Unit cycles on high/low pressure
limit.
D. Unit blows fuses or trips circuit
breaker.
1. Check power supply for adequate
phase and voltage. Check wiring
to unit and external breakers or
fuses.
2. Check internal circuit protection
devices for continuity.
3. Check operation of wall-mounted
thermostat.
4. Reset pressure switch.
5. Check for loose wiring. Check
components for failure.
PROBLEM / SYMPTOM
LIKELY CAUSE(S)
CORRECTION
A. Unit does not run.
1. Power supply problem.
2. Tripped internal disconnect.
3. Shut off by external thermostat
or thermostat is defective.
4. Unit off on high or low
pressure limit.
5. Internal component or
connection failure.
4.2 F
AILURE
S
YMPTOMS
G
UIDE
NOTE: An internal anti-
short-cycle timer
will prevent the unit
from starting for .2
to 8 minutes
following start-up.
