Johnson Controls HVWHP072B32S - Page 78

3-58
SM-18006
TROUBLESHOOTING
Cause Check Item
Action
(Turn OFF Main Switch)
Event
Decrease of
Discharge Gas
Superheat
Check thermistor is
correctly installed.
Faulty
Discharge
Gas
Thermistor
Failure
Replace thermistor
if faulty.
Correctly install it.
Incorrect
Installation
Check connection.
T ighten, replace
connector or
repair connection
Incorrect
Connection
Check connections.
Replace W.S. PCB and
check operation.
Faulty
W.S. PCB
Failure
Replace W.S. PCB
if faulty.
Repair wiring
connection.
Disconnected
Wires for
Expansion
Valve Control
Check refrigerant piping
and communication
cable.
Repair cable correctly.
Refrigerant piping and
communication cable do not
match within the same
refrigerant system group.
Check operating
pressures.
Charge correct amount
of refrigerant.
Overcharged Refrigerant
Check expansion valve.
Replace expansion
valve if faulty.
Faulty Expansion Valve
Check resistance
of thermistor.
(Refer to Section 4.2.1.7.)