Hitachi RAS-(4-12)HNP(1)(E) - Page 229

8 Troubleshooting
215
SMGB0087 rev.0 - 12/2013
8
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
Cooling or heating
process with an
abnormal sound
Foreign particles inside of the fan casing Visually inspect it Remove the foreign particles
Indoor unit fan runner is hitting the casing Visually inspect it
Adjust the position of the fan
runner
Outdoor unit propeller fan is hitting the shroud Visually inspect it
Adjust the position of the
propeller fan
Abnormal sound from
the compressor
Faulty Installation
Check that each part is
tightly xed
Tightly x each part
Liquid refrigerant
compression
Adjust the suction gas
temperature and pressure
Ensure superheat
Wear or breakage of
the internal
compressor parts
Abnormal sound from the
inside of the compressor
Replace the compressor
No heating by the oil
heater
Check the resistance (oil
heater, fFuse)
Replace the oil heater or the
fuse
Humming sound from the magnetic conductor
Check the surface of the
contacts
Replace the magnetic switch
Abnormal vibration of the cabinets Check each xing screw Tightly x each screw
Outdoor fan does not
operate when the
compressor operates
Obstacle at the outdoor fan Check the obstacles Remove the obstacles
Watching condition for the heating process
Wait for the switching of the
4-way valve (1 ~ 3 minutes)
If the 4-way valve does not
switch, check for insufcient
refrigerant
Indoor fan does not
operate when the
compressor operates
Discharge pressure does not increase higher
than 1.5 Mpa due to the insufcient refrigerant
Check the operation
pressure *5)
Add the refrigerant
Disconnected wiring for the indoor fan Check the wiring Connect the wiring correctly
N O T E
• *1): Refer to section “Self-checking procedure of the remote control switch”.
• *2): Refer to section “Self-checking procedure of PCB by means of the Remote Control Switch”.
• *3): Even if the remote control switches are normal, the compressor does not operate under the following conditions:
1. Indoor temperature is lower than 21ºC or outdoor temperature Is lower than -5ºC during the cooling process
(DB).
2. Indoor temperature is higher than 27ºC (DB) or outdoor temperature is higher than 15ºC (WB) during the heating
process.
3. When a cooling (or heating) process signal is given to the outdoor unit and a different mode as heating (or cool-
ing) process signal is given to the indoor units.
4. When an emergency stop signal is given to outdoor unit.
• *4): Refer to chapter “3. Piping work and refrigerant charge”.
• *5): Refer to chapter “7. Test run”.