Hitachi Utopia RPI-2.5HRG Service Manual page 19

TROUBLESHOOTING
(1.1.6 Abnormalities of Devices)
Phenomenon
Cooling or
Heating
Operation
with
Abnormal
Sound
1-16
Cause
Foreign Particles Inside
of Fan Casing
Indoor Unit Fan Runner
is Hitting Casing
Outdoor Unit Propeller Fan
is Hitting Shroud
Faulty
Installation
Liquid Ref.
Abnormal
Compression
Sound from
Compressor
Wear or
Breakage of
Internal
Comp. Parts
Hamming Sound from
Magnetic Conductor
Abnormal Vibration of
Cabinets
Check Item
Check it by viewing.
Check it by viewing.
Check it by viewing.
Check each part is
tightly fixed.
Check expansion valve
opening.
Abnormal Sound from
Inside of Compressor
Check surface of
contacts.
Check each fixing
screws.
Action
(Turn OFF Main Switch)
Remove foreign
particles.
Adjust position of
fan runner.
Adjust position of
propeller fan.
Tightly fix it.
Ensure superheat.
Replace compressor.
Replace magnetic
switch.
Tightly fix it.