TROUBLE SHOOTING GUIDE FOR UNITS WITH DX COOLING
8
Complaint
Symptoms
Probable Cause
Recommended Action
Ref.
Note
1. Normal operation
except too frequent
stopping and starting.
Intermittent contact
in electrical control
circuit.
Repair or replace faulty control.
a. Low-pressure
control differential
set too close.
a. Reset differential in accordance
with job conditions.
b. Lack of
refrigerant.
b. Repair refrigerant leak and
recharge.
1
2. Normal operation
except too frequent
stopping and starting
on low-pressure
controls switch.
c. Reduced airflow.
1) Dirty coil
2) Dirty air filters
3) Broken fan belt
4) Improper fan belt
tension.
c. Clean coil, filters and check fan
drive.
3. Suction pressure too
low, frosting at filter-
drier.
Restricted liquid
line filter-drier.
Replace core.
2
B. Compressor "Short Cycles"
4. Compressor will not
load or unload. Cuts
out on low-pressure
switch.
Inoperative
compressor
unloading system.
Repair or replace faulty control.
1. Oil level too low.
Insufficient oil
charge.
Add oil.
a. Improper pipe
size or design.
a. Resize lines, provide oil lift
traps.
2. Oil level gradually
drops.
b. Liquid flood-
back. (Excessively
cold section).
b. Readjust superheat setting;
check remote bulb contact with
suction line.
5
C. Compressor looses oil.
3. Oil around
compressor base and
low crankcase.
Crankcase fittings
leak oil.
Repair oil leaks and add proper
compressor oil.
