Carrier 48NHT024 - Page 24

FLARE NUT STRAINER RETAINER COOLING
FLARE
NUT
A87277
Fig. 15—Metering Device Components
Table 19—Cooling Service Analysis Chart
SYMPTOM
CAUSE
REMEDY
Compressor and
condenser fan
will not start.
Power failure
Call power company.
Fuse blown or circuit breaker tripped
Replace fuse or reset circuit breaker.
Defective thermostat, contactor, transformer, or
control relay
Replace component.
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 start
but condenser fan runs.
Faulty wirjng or loose connections in compressor
circuit
Check wiring and repair or replace.
Compressor motor burned out, seized, or internal
overload open
Determine cause. Replace compressor.
Defective run/start capacitor, overload, start relay
Determine cause and replace.
One leg of three-phase power dead
Replace fuse or reset circuit breaker.
Determine cause.
Compressor cycles.
(other than normally
satisfying thermostat)
Refrigerant overcharge or undercharge
Blow refrigerant, evacuate system, and recharge to
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, or start relay
Determine cause and replace.
Defective thermostat
Replace thermostat.
Faulty condenser fan motor or capacitor
Replace.
Restriction in refrigerant system
Locate restriction and remove.
Compressor operates
continuously.
Dirty air filter
Replace filter.
Unit undersized for load
Decrease load or increase unit size.
Thermostat set too low
Reset thermostat.
Low refrigerant charge
Locate leak, repair, and recharge.
Leaking valves in compressor
Replace compressor.
Air in system
Blow refrigerant, evacuate system, and recharge.
Condenser coil dirty or restricted
Clean coil or remove restriction.
Excessive head pressure
Dirty air filter
Replace filter.
Dirty condenser coil
Clean coil.
Refrigerant overcharged
Purge excess refrigerant.
Air in system
Blow refrigerant, evacuate system, and recharge.
Condenser air restricted or air short-cycling
Determine cause and correct.
Head pressure too low
Low refrigerant charge
Check for leaks, repair, and recharge.
Compressor valves leaking
Replace compressor.
Restriction in liquid tube
Remove restriction.
Excessive suction
pressure
High heat load
Check for source and eliminate..
Compressor valves leaking
Replace compressor.
Refrigerant overcharged
Purge excess refrigerant.
Dirty air filter
Replace filter.
Low refrigerant charge
Check for leaks, repair, and recharge.
Metering device or low side restricted
Remove source of restriction.
Suction pressure too low
Insufficient evaporator airflow
Increase air quantity. Check filter—replace if
necessary.
Temperature too low in conditioned area
Reset thermostat.
Outdoor ambient below 55 F
Install low-ambient kit.
Field-installed filter-drier restricted
Replace.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
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Tab I la I la
PC 101 Catalog No. 564-816
Printed in U.S.A.
Form 48NT-9SI Pg 24 9-88
Replaces: 48NT-8SI