Ice ECUA90 Installation & Operation Manual page 23

PROBLEM/SYMPTOM
B. Unit runs for long periods or continu-
ously; cooling is insufficient.
C. Unit cycles on high/low pressure
limit.
D. Unit blows fuses or trips circuit
breaker.
E. Water on floor near unit.
F. No space heating or reduced heating
(units equipped with resistance ele-
ments)
LIKELY CAUSE(S)
1. Dirty filter or reduced airflow
2. Low refrigerant.
3. Component failure.
4. Unit undersized for job.
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 volt-
age or phase loss (3ø only).
1. Obstruction in condensate line.
2. Obstruction or leak in condensate
pan.
3. Unit is not level.
1. Defective heating element(s).
2. Thermal limit open.
3. Defective heater contactor.
23
CORRECTION
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
approximately 60 PSIG (low pressure) and 650 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 dia-
grams. Test components (especially the compressor)
for shorts.
4. Note voltage range limitations specific to the com-
pressor troubleshooting section.
1. Check for clog or restriction.
2. Check pan for leak or blockage.
3. Level unit.
1. Check resistance element(s) for continuity.
2. Check continuity across thermal limit switch.
3. Check relay for proper operation. Replace if defective.
ECU 04/2015 rev.3