Carrier SUPRA 950Mt - Expansion Valve Malfunction; Hot Gas Valve Malfunction

62-11863 6-6
6.4 STANDBY MOTOR MALFUNCTION
6.3.11 Expansion Valve Malfunction
Low suction pressure with high
superheat
Low refrigerant charge
External equalizer line plugged
Ice formation at valve seat
Wax, oil or dirt plugging valve or orifice
Broken capillary
Power assembly failure or partial
Loss of element/bulb charge
Superheat setting too high
5.5 / 5.7
Clean
5.6
5.16
5.16
Replace
Replace
5.16
Low superheat and liquid slug-
ging in compressor
Superheat setting too low
External equalizer line plugged
Ice holding valve open
Foreign material in valve
Pin and seat of expansion valve eroded or held open by
foreign material
5.16
Open
5.6
Clean
5.16
Fluctuating suction pressure Improper bulb location or installation
Low superheat setting
5.16
5.16
High superheat Broken capillary 5.16
6.3.12 Hot Gas Valve Malfunction
Valve does not function prop-
erly
No power to valve
Improper wiring or loose connections
Coil defective
Valve improperly assembled
Coil or coil sleeve improperly assembled
Temperature controller malfunction
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
5.10.2
5.10.3
5.10.2
Replace
5.10.2 / 5.10.3
5.10.2 / 5.10.3
5.10.2
Standby motor fails to start Motor contactor (MC) defective
Motor Overload (OL) open
Improper power supply
Oil pressure switch (OPS) closed or grounded
Cab Command defective
Replace
Replace motor
2.7.6
Replace
Replace
Standby motor starts, then
stops
Motor Overload (OL) open
High amperage draw
2.7.6
Check