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TROUBLESHOOTING
Cooling
SYMPTOM
CAUSE
REMEDY
Compressor
and
Power
failure
Call power
company.
condenser
fan will
Fuse blown
or circuit
breaker
tripped
Replace
fuse or reset circuit
breaker.
not start.
Defective
thermostat,
contactor,
transformer,
Replace
component.
or control
relay
Insufficient
line voltage
Determine
cause
and correct.
Incorrect
or faulty wiring
Check
wiring
diagram
and rewire
correctly.
Thermostat
setting
too high
Lower
thermostat
setting
below
room
temperature.
Compressor
will
not
Faulty wiring
or loose connections
in
Check
wiring
and repair
or replace.
start
but condenser
compressor
circuit
fan
runs.
Compressor
motor
burned
out, seized,
or
Determine
cause.
Replace
compressor.
internal
overload
open
Defective
run/start
capacitor,
overload,
Determine
cause
and replace.
start
relay
One leg of 3-phase
power
dead
Three-phase
scroll
compressor
(Unit
sizes
048,060
only)
makes
excessive
noise,
and there
may
be a low pres-
sure
differential.
Compressor
cycles
(other
than
normally
satisfying
thermostat).
Scroll
compressor
is rotating
in the
wrong
direction
Replace
fuse or reset circuit
breaker.
Determine
cause.
Correct
the direction
of rotation
by reversing
the
3-phase
power
leads to the unit. Shut down
unit to
allow pressures
to equalize.
Refrigerant
overcharge
or undercharge
Recover
refrigerant,
evacuate
system,
and
recharge
to capacities
shown
on nameplate.
Defective
compressor
Replace
and determine
cause.
Insufficient
line voltage
Determine
cause
and correct.
Blocked
condenser
Determine
cause
and correct.
Defective
run/start
capacitor,
overload
Determine
cause
and replace.
or start
relay
Defective
thermostat
Replace
thermostat.
Faulty
condenser-fan
motor
or capacitor
Replace.
Restriction
in refrigerant
system
Locate
restriction
and remove.
Compressor
Dirty
air filter
Replace
filter.
operates
Unit undersized
for load
Decrease
load or increase
unit size.
continuously.
Thermostat
set too low
Reset
thermostat.
Low refrigerant
charge
Locate
leak, repair, and recharge.
Leaking
valves
in compressor
Replace
compressor.
Air in system
Recover
refrigerant,
evacuate
system,
and recharge.
Condenser
coil dirty or restricted
Clean
coil or remove
restriction.
Excessive
head
Dirty
air filter
Replace
filter.
pressure.
Dirty
condenser
coil
Clean
coil.
Refrigerant
overcharged
Recover
excess
refrigerant.
Air in system
Recover
refrigerant,
evacuate
system,
and recharge.
Condenser
air restricted
or air short-cycling
Determine
cause
and correct.
Head
pressure
too
Low refrigerant
charge
Check
for leaks,
repair
and recharge.
low.
Compressor
valves
leaking
Replace
compressor.
Restriction
in liquid tube
Remove
restriction.
Excessive
suction
High heat load
Check
for source
and eliminate.
pressure.
Compressor
valves
leaking
Replace
compressor.
Refrigerant
overcharged
Recover
excess
refrigerant.
Suction
pressure
Dirty
air filter
Replace
filter.
too low.
Low refrigerant
charge
Check
for leaks,
repair
and recharge.
Metering
device
or low side restricted
Remove
source
of restriction.
Insufficient
evaporator
airflow
increase
air quantity.
Check
filter --
replace
if
necessary.
Temperature
too low in conditioned
area
Reset
thermostat.
Outdoor
ambient
below
40 F
install
low-ambient
kit.
Field-installed
filter-drier
restricted
Replace.
--34--
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