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Electric Standby Mechanical Diagnosis
CONDITION
POSSIBLE CAUSE
REMEDY
Compressor does not run
Improperly wired
Check wiring against diagram
Low line voltage
Check line voltage—determine
location of voltage drop
Relay contacts not closing
Check and replace relay if defective
Power relay open
Check relay, replace if defective
Motor wiring defective—open circuit
Close power supply start or
disconnect switch
Tripped circuit breaker
Reset
Open circuit in motor winding
Check stator leads. If leads OK,
replace stator
High pressure cutout switch open
Eliminate cause of excessive
pressure
Thermostat faulty
Repair or replace
Compressor piston stuck
Replace compressor
Frozen compressor or motor
bearings
Repair or replace
Shortage of refrigerant
Recharge
Low pressure cutout switch open
Recharge
Overload relay open
Reset
Unit short cycles
Evaporator fan rotating in wrong
direction
Correction rotation
Shortage of refrigerant (low pressure
cutout)
Repair leak and recharge
Restricted expansion valve (low
pressure cutout)
Replace expansion valve
Refrigerant overcharge (high
pressure cutout)
Remove excess charge
Cycling on high pressure cutout
Check air flow and fan
Clogged condenser coil
Clean coil
Summary of Contents for 914 724
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Page 107: ...97 Model 10 and 20 Schematic Diagram...
Page 108: ...98 Model 10 Wiring Diagram...
Page 109: ...99 Model 20 Wiring Diagram...
Page 110: ...100 Model 20 Single Phase with Heat Option Schematic Diagram...