Hitachi UTOPIA RAS-4HVRP2E - Page 234

10 Troubleshooting
Initial troubleshooting
SMGB0136 rev.0 - 07/2021
232
Phenomenon
Cooling or Heating
Operation with
abnormal sound
Outdoor Fan is not
operated when
compressor is operated
Indoor Fan is not
operated when
compressor is operated
Cause
Foreign particles inside of fan casing
Indoor unit fan runner is hitting casing
Outdoor unit propeller fan is hitting
shroud
Abnormal sound
from compressor
Failure of
installation
Liquid refrigerant
compression
Wear or breakage
of internal
compressor parts
Crankcase heater
does not get
warm
Hamming sound from magnetic
conductor
Abnormal vibration of cabinets
Obstacle at Outdoor fan
Preparatory state for heating operation
Discharge pressure does not increase
higherthan2.2MPaduetoinsufcient
refrigerant
Disconnected wiring for indoor fan
Failure of indoor unit PCB
Check Item
Check it by viewing
Check it by viewing
Check it by viewing
Checkeachpartistightlyxed
Check expansion valve opening
Abnormal sound from inside of
compressor
Check resistance (Crankcase
heater, fuse)
Check surface of contacts
Checkeachxingscrews
Check obstacles
Wait for switching of reversing
valve (1 to 3 minutes)
Check operation pressure
Check wiring
Check indoor unit PCB
Action (Turn OFF
Main Switch)
Remove foreign particles
Adjust position of fan runner
Tightlyxit
Ensure superheat
Replace compressor
Replace crankcase heater orr
fuse
Replace magnetic switch
Tightlyxit
Remove obstacles
In case that reversing valve
is not switched, check for
insufcientrefrigerant.
Add refrigerant
Connect wiring correctly
Replace indoor unit PCB
Adjust position of propeller fan