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10--Trou
b[eshooting--Coo[ing
SYMPTOM
Compressor
and condenser
fan wiil
not start.
Compressor
will
not
start
but
condenser
fan
runs.
CAUSE
Power Failure
Fuse blown or circuit breaker tripped
Defective thermostat,
contractor,
transformer,
or
control relay
Insufficient
line voltage
Incorrect or faulty wiring
Thermostat
setting too high
Faulty wiring or loose connections
in compressor
circuit
Compressor
motor burned out, seized, or internal
overload open
Defective
run/start capacitor,
overload,
start relay
One leg of 3-phase power dead
Three-phase
scroll
compressor
(PAl P048,
PA2P030o060}
makes
excessive
noise, and
Scroll compressor
is rotating
there
may be a low pressure differential
inthe wrong direction
Compressor
cycles
(other
than
normally
satisfying
thermostat),
Compressor
operates
continuously.
Excessive
head pressure.
Head
pressure
too
low.
Excessive
suction
pressure,
Suction
pressure
too
low.
Refrigerant
overcharge
or undercharge
Defective
compressor
Insufficient
line voltage
Blocked condenser
Defective run/start capacitor, overload
or start
relay
Defective thermostat
Faulty condenser-fan
motor or capacitor
Restriction
h_ refrigerant
system
Dirty air filter
Unit undersized
for load
Thermostat
set too low
Low refrigerant
charge
Leaking valves in compressor
Air in system
Condenser
coil dirty or restricted
Dirty air filter
Dirty condenser
coil
Refrigerant
overcharged
Air in system
Condenser
air restricted
or air short-cycling
Low refrigerant
charge
Compressor
valves leaking
Restriction
in liquid tube
High heat load
Compressor
valves leaking
Refrigerant
overcharged
Dirty air filter
Low refrigerant
charge
Metering device or low side restricted
Insufficient
evaporator
airflow
Temperature
too low in conditioned
area
Outdoor
ambient below 40°F
Field-installed
filter-drier
restricted
REMEDY
Call power company
Replace fuse or reset circuit breaker
Replace component
Determine
cause and correct
Check wiring diagram
and rewire correctly
Lower thermostat
setting below
room temperature
Check wiring and repair or replace
Determine
cause
Replace compressor
Determine
cause and replace
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.
Recover refrigerant,
evacuate
system,
and re-
charge to capacities
shown on nameplate
Replace and determine
cause
Determine
cause and correct
Determine
cause and correct
Determine
cause and replace
Replace thermostat
Replace
Locate restriction and remove
Replace filter
Decrease
load or increase
unit size
Reset thermostat
Locate leak, repair, and recharge
Replace compressor
Recover
refrigerant, evacuate
system,
and re-
charge
Clean coil or remove restriction
Replace filter
Clean coil
Recover excess
refrigerant
Recover
refrigerant, evacuate
system,
and re-
charge
Determine
cause and correct
Check for leaks
repair and recharge
Replace compressor
Remove restriction
Check for source and eliminate
Replace compressor
Recover excess
refrigerant
Replace Filter
Check for leaks, repair, and recharge
Remove source of restriction
Increase air quantity
Check filter- replace if necessary
Reset thermostat
Install low-ambient
kit
Replace
2?
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