Carrier 51CM - Manual (Page 18)

TROUBLESHOOTING
NO COOLING OR INSUFFICIENT COOLING
Compressor Does Not Run
OPENING IN POWER CIRCUIT
Control off
Blown fuse
Defective wiring
Defective service cord
Loose electrical connections
Faulty switches, theimostat oi fan
COMPRESSOR POWER SUPPLY OPEN
Loose leads at compiessoi teiminals
Detective motor overload switch
Defective capacitor
Open compressoi windings
Seized compressor
Compressor Runs But Cycles
FAN OPERATING ERRATICALLY
Loose lead at fan motoi
Motor defective or burned out
Outdooi air restricted or leciiculating
OVERCHARGE OR NONCONDENSABLES IN
SYSTEM
RESTRICTED DISCHARGE LINE
CYCLES ON COMPRESSOR OVERLOAD
Defective lun capacitor
Defective compìessor beatings oi valves
Gieatly restricted indoor ait (iced indoor coil)
Low lefrigerant charge
Indooi capillary restricted
Liquid line lestiicted
Compressor hot
Compressor Runs But Insufficient Cooling
COOLING AIR NOT ADEQUATE
Dirty filter 01 coil
Iced evaporator coil (slightly low lefiigerant
chaige)
Defective fan motor
CONDENSER AIR NOT ADEQUATE
Outside air restricted
Dirty coil
Defective Ian motoi
UNIT UNDERSIZE
AIR LEAKAGE
LIQUID LINE SLIGHTLY RESTRICTED
Capillary restricted
COMPRESSOR FLOODING
Unit oveichaiged
SERVICE POINTS
(Check Annually)
1 Clean evaporator and condenser coils Indoois —
Use a hooked wire or bristle brush to lemove dirt
from fins Outdoors — Use compressed air or a
vacuum cleanei
2 Clean basepan and othei painted surfaces
3 Clean all drain passages
4 Clean motor and fans
5 Vacuum clean the insulation
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9
10
11
Paint paits that show evidence of lust with a good
lust-resistant paint
Check relrigerant connections foi evidence of
leakage Repair if necessaiy
Check wires lot deteiioiation
Check damper contiols
Fans should be tight on motoi shaft
Run the unit and eliminate any piping vibiation
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