Alarm Codes - Hitachi RASC-4HNPE Service Manual

10 Troubleshooting
Troubleshooting procedure

10.2.2 Alarm codes

• The RUN LED flickers and "ALARM" is displayed on the remote control switch.
• The unit number, the alarm code and the unit code are alternately displayed on the set temperature section.
• The unit number and the alarm code are displayed on the 7 segments of the RASC unit PCB and Remote control
Screen (if installed).
Code
Category
number
1 Indoor unit Activation of protection device (float switch)
Protection
2 Activation of protection device
device
Abnormal transmission between RASC and
3
indoor units
Transmission
Abnormal transmission between inverter PCB
4
and RASC unit PCB
Reception of abnormal operation code for
5 Power supply
detection of power source phase
Excessively low voltage or excessively high
6 Voltage
voltage for the inverter
7 Decrease in discharge gas superheat
Cycle
Excessively high discharge gas temperature at
8
the top of compressor
11 Air inlet thermistor
12 Air outlet thermistor
Indoor unit
sensor
13 Freeze protection thermistor
14 Gas piping thermistor
15 Econofresh Thermistor of fresh outdoor air
16 Remote thermistor
Indoor unit
sensor
17 Thermistor of remote control switch
Activation of the protection device for the
19 Fan motor
indoor fan motor
Thermistor for discharge gas temperature
20
(THM9)
21 High pressure sensor
RASC unit
Thermistor for outdoor ambient temperature
sensor
22
(THM7)
Thermistor for evaporating temperature
24
(THM8)
Incorrect capacity setting or combined capacity
31
between RASC and indoor units
35 Incorrect indoor unit number setting
System
36 Incorrect of Indoor Unit Combination.
Abnormality of picking up circuit for protection
38
(RASC unit)
197 SMGB0091 rev.2 - 11/2015
Type of abnormality Main cause
Failure of fan motor, drain discharge, PCB, relay,
float switch activated (High Water Level in Drain Pan,
Abnormality of Drain Pipe, Float Switch or Drain Pan).
Activation of the float switch (FS).
Activation of the internal thermostat protection of the
motor (ITO).
Activation of the high pressure switch (PSH).
Variable frequency driver failure (VFD).
Incorrect wiring. Loose terminals, Failure of PCB.
Tripping of fuse. Power supply OFF.
Transmission failure between inverter PCBs. (Loose
Connector, Wire Breaking, Blowout of Fuse).
Power source with abnormal wave pattern. Main power
supply phase is reversely connected or one phase is
not connected.
Voltage drop in power supply. Incorrect wiring or
insufficient capacity of power supply wiring.
Excessive Refrigerant Charge, Failure of Thermistor,
Incorrect Wiring, Incorrect Piping Connection,
Expansion Valve Locking at Opened Position
(Disconnected Connector) or faulty RASC fan motor.
Insufficient refrigerant charge, refrigerant leakage.
Expansion valve closed or clogged.
Failure of thermistor, sensor, connection. (Incorrect
Wiring, Disconnected Wiring, Wire Breaking, Short
Circuit).
Failure of fan motor.
Incorrect wiring, disconnected wiring, broken cable,
short circuit.
Incorrect Capacity Code Setting, Excessive or
Insufficient Indoor Unit Total Capacity Code.
Duplication of indoor unit number. Number of indoor
units over specifications.
"Indoor Unit is Designed for Other Refrigerant (R22
or R407C)".
Failure of indoor unit PCB, incorrect wiring, connection
to PCB in indoor unit.
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