Hitachi UTOPIA RAS-4 Series - Alarm Codes

11 Troubleshooting
Alarm codes
TCGB0136 rev.1 - 05/2021
120
11.2 Alarm codes
Code Category Content of Abnormality Leading Cause
01 Indoor unit
Activation of protection device (Float
switch (*))
Activationofoatswitch(Highwaterlevelindrainpan,
abnormalityofdrainpipe,oatswitch,ordrainpan)
02 Outdoor unit
Activation of protection device (High
pressure cut or High compressor
temperature cut)
Activation of PSH (pipe clogging, excessive refrigerant, inert
gas mixing) or activation of High temperature compressor
thermostat (shortage of refrigerant or system refrigerant
leakage)
03
Communication
Abnormal communication between Indoor
units and outdoor units
Incorrect wiring, loose terminals, disconnected
communication cable, blowout of fuse, indoor unit power
OFF, Outdoor fuse meltdown
04
Abnormal communication between
inverter PCB and Outdoor PCB
Inverter PCB - outdoor PCB communication failure (loose
connector, wire breaking, blowout of fuse)
05 Supply phase Abnormality of power supply phases Incorrect power supply, open-phase
06 Voltage Abnormal inverter voltage Outdoorvoltagedecrease,insufcientpowercapacity
07
Cycle
Decrease in discharge gas superheat
Excessive refrigerant charge, failure of thermistor, incorrect
wiring, incorrect piping connection, expansion valve locking
at opened position (Disconnect connector)
08
Excessively high discharge gas
temperature
InsufcientRefrigerantCharge,PipeClogging,Failureof
Thermistor, Incorrect Wiring, Incorrect Piping Connection,
Expansion Valve Locking at Closed Position (Disconnect
Connector)
09 Fan motor
Activation of protection device for outdoor
fan
Fan motor overheat, locking
0A Communication
Abnormal communication between
outdoor units
Incorrect wiring, broken cable, loose terminals
0b
Outdoor unit
Incorrect outdoor unit address setting
Duplication of address setting for outdoor units (Sub units) in
same refrigerant cycle number
0C
Main unit of the outdoor unit incorrectly
set
Two (or more) outdoor units set as "Main Unit" exist in same
refrigerant cycle number
11
Sensor on Indoor
Unit
Abnormality of inlet air thermistor
Incorrect wiring, disconnecting wiring,
breaking wire, short circuit
12 Abnormality of outlet air thermistor
13
Abnormality of freeze protection
thermistor
14 Abnormality of gas piping thermistor
15
Abnormality of outdoor air thermistor
(Econofresh)
16 Abnormality of remote sensor (DOAS)
17
Abnormality of thermistor built-in remote
Controller (DOAS)
18
Indoor fan motor
Abnormality of indoor fan system
Abnormality of indoor fan motor (Step-out), indoor fan
controller failure
19
Activation of protection device for indoor
fan
Fan motor overheat, lockup
1A
Indoor fan
controller
Abnormalityoffancontrollern
temperature
Abnormalityofnthermistororfancontroller,heat
exchanger clogging, abnormality of fan motor
1b Activation of overcurrent protection Abnormality of fan motor
1C Problem with current sensor Abnormality of fan controller current sensor
1d Activation fan controller protection Driver IC error signal detection, instantaneous overcurrent
1E
Abnormality of indoor fan controller
voltage
Indoorvoltagedecrease,insufcientcapacityofpower
supply wiring
20
Sensor on
Outdoor Unit
Abnormality of the compressor thermistor
21 Abnormality of high pressure sensor
Incorrect wiring, disconnecting wiring,
breaking wire, short circuit
22 Abnormality of outdoor air thermistor
24
Abnormality of heat exchanger liquid pipe
thermistor