Carrier 48N - Manual (Page 24)

FLARE NUT STRAINER RETAINER COOLING
TO
INDOOR
COIL
FLARE
NUT
(TOWARD INDOOR COIL)
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
controi 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 wiring 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.
Suction pressure too low
Dirty air filter Replace filter.
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 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.
^ PC 101 Catalog No. 564-816 Printed in U.S.A. Form 48NT-9SI Pg 24 9-88 Replaces: 48NT-8SI
Tab I la I la