Hitachi Utopia PAS-3HVRG, Service Manual

Page: 45 / 127

TROUBLESHOOTING
1-42
Alarm
Code
Heating Overload
(High Pressure Switch will be Activate)
This alarm code is indicated when the protection device is activated at following condition.
Liquid refrigerant piping temperature of indoor unit is more than 55 degree and top of compressor
temperature is more than 95 degree.
Yes Yes Yes
Yes
Faulty PCB1.
No No No
Faulty PCB1.
No
Is CMC ON?
Is CMC ON more
than 3 seconds?
Is protection
device activated?
Is the voltage between
PCN9#1 and #3
220V/240V?
Check the following value by remote control switch.
1. Top of Compressor Temperature: 95
o
C or less
2. Liquid Refrigerant Piping Temperature of Indoor Unit: 55
o
C or less
If exceeding the above value, repair it.
Cause Check Item
Action
(Turn OFF Main Switch)
Phenomenon
Clogging of
Heat Exchanger
Remove it.
Remove it.
Remove it.
Check for dust on
air filter.
Check for any obstacle
at inlet or outlet of
heat exchanger.
Check the service space.
Check for fan speed.
( Cooling: Outdoor Fan
Heating: Indoor Fan)
Secure service space.
Replace fan motor
if faulty.
Insufficient Air Flow
to Heat Exchanger
of Indoor Unit
Activation of
High Pressure
Switch due to
Excessively
High Discharge
Pressure
during Heating
Operation