Hitachi RPI-0.8FSG1 Service Manual page 37

Phenomenon
Activation of
High Pressure
Switch due to
Excessively
High Discharge
Pressure
Mixture of Non-Condensable
Gas in Refrigerant Cycle
Clogging of Discharge Piping
Cause
Faulty or Malfunction of
Expansion Valve
Faulty Gas Bypass
Solenoid Valve
Overcharged Refrigerant
Liquid Line Stop Valve or
Gas Line Stop Valve are
not in Operation
Clogging of Check Valve
Check Item
Check for clogging.
Check connecting
wiring and connectors.
Check operating sound
from coil.
Check discharge gas
thermistor.
Check attaching
state of discharge
gas thermistor.
Check for clogging.
Check cycle operating
temp. and expansion
valve opening.
Check ambient temp.
and pressure.
Check for clogging.
Check stop valves.
Check for clogging.
TROUBLESHOOTING
Action
(Turn OFF Main Switch)
Remove clogging.
Replace connector.
Replace coil.
Replace thermistor.
Reattach thermistor.
Replace gas bypass
solenoid valve.
Charge refrigerant
correctly.
Recharge refrigerant
after vacuum pumping.
Remove clogging.
Fully open stop valve.
Replace check valve.
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