Carrier 48GH - Manual (Page 22)

SYMPTOM
Compressor and
Condenser Fan Will
Not Start
Compressor Will Not Start
But Condenser Fan Runs
Compressor Cycles (other
than normally satisfying
thermostat)
Compressor Operates
Continuously
Excessive Head Pressure
Head Pressure Too Low
Excessive Suction
Pressure
Table 8 — Cooling Service Analysis Chart
CAUSE
Power failure
Fuse blown or circuit breaker
gripped________
Defective thermostat, contactor,
transformer, or control relay
insufficient line voltage
Incorrect or faulty wiring
Thermostat setting too high
Suction Pressure Too Low
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 three-phase power dead
Refrigerant overcharge or
undercharge
Defective compressor
insufficient line voltage
Blocked condenser
Defective run/start capacitor,
overload, or start relay
Defective thermostat
Fauity condenser fan motor or
capacitor
Restriction in refrigerant system
Dirty air filter
Unit undersized for load
REMEDY
Call power company.
Repiace fuse or reset circuit breaker
Replace component
Determine cause and correct.__________
Check wiring diagram and rewire corr^tly.
Lower thermostat setting beiow room
temperature __ ^______________
Check wiring and repair or replace
Determine cause Replace compressor
Determine cause and replace.
Replace fuse or reset circuit breaker Determine
cause.
___ ______ ___ _________ _
Blow refrigerant, evacuate system, and recharge
to nameplate __
Replace and determine cause.
Determine cause and correct _
Determine cause and correct _
Determine cause and replace.
Replace thermostat.
Replace
Locate restriction and remwe
Replace filter.
Thermostat set too low
Low refrigerant charge
Leaking valves in compressor
Àir 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 55 F
Field-installed filter-drier
restricted
Decrease load or increase unit size
Reset thermostat. ___ _______________
Locate leak, repair, and recharge
Replace compressor
Blow refrigerant, evacuate system, and recharge
Clean coil or remove restriction____
Replace filter
Clean coil __ _________
Purge excess refrigerant _____
Blow refrigerant, evacuate system, and recharge.
Determine cause and correct
Check for leaks, repair, and recharge
Repiace compressor. _ ______
Remove restriction
Check for source and eliminate
Replace compressor
Purge excess refrigerant___________ __
Replace filter. ________
Check for leaks, repair, and recharge.
Remove source of restriction
Increase air quantity Check filter
if necessary. replace
Reset thermostat
Install accessory low-ambient kit
Replace
For replacement items use Carrier Specified Parts.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Form 48GH,GL-1 SI New PrintedinUSA 2-81 PC101 Catalog No 534-820 Book 1
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