3-5
62-10630
Table 3-2 Mechanical Indications -- Continued
INDICATION/TROUBLE
POSSIBLE CAUSES
REFERENCE
SECTION
3.2.10 Expansion Valve
Low suction pressure with high
superheat
Low refrigerant charge
External equalizer line plugged
Ice wax, oil or dirt plugging valve strainer
Broken capillary
Superheat setting too high
4.10.1
Repair
4.6
Repair
4.16.2
Low superheat and liquids lug-
ging in compressor
Superheat setting too low
External equalizer line plugged
Pin and seat of expansion valve eroded or held open by
foreign material
4.16.2
Repair
4.16
Fluctuating suction pressure
Improper bulb location or installation
Insulation missing from sensing bulb
Low superheat setting
4.16
Replace
4.16.2
High superheat
Expansion valve setting
4.16.2
3.2.11 Malfunction Hot Gas Solenoid or Condenser Pressure Regulating Valve
Valve does not function properly
No power to valve
Improper wiring or loose connections
Valve improperly assembled
Coil or coil sleeve improperly assembled
Movement of plunger restricted due to:
a. Corroded or worn parts
b. Foreign material lodged in valve
c. Bent or dented enclosing tube
Check
Check
4.14
Valve shifts but refrigerant
continues to flow
Foreign material lodged under seat
Defective seat
4.14
3.2.12 Standby Compressor Malfunction
Standby compressor fails to start
Motor contactor defective
Motor Overload open
Improper power supply
5–minute timer active
Replace
Check
Correct
Check
Standby motor starts, then stops
Motor Overload open
Check