Mitsubishi Electric PUHY-HP144TSHMU-A Service Handbook page 100

[ VII Control ]
-12- Emergency Operation Mode
1. Problems with the outdoor unit
HP144 and HP192 models operate in emergency operation mode when one of the outdoor unit is trouble or when one or two
of the outdoor units are in trouble. The outdoor unit, which is not in trouble, operates in this mode.
This mode can be started by performing an error reset via the remote controller.
(1) Starting the emergency operation
1) When an error occurs, the error source and the error code will be displayed on the display on the remote controller.
2) The error is reset using the remote controller.
3) If an error code appears that permits an emergency operation in step 1) above, (See the table below.), the retry operation
starts.
4) If the same error is detected during the retry operation (step 3 above), an emergency operation can be started by resetting
the error via the remote controller.
Error codes that permit an emergency operation (Applicable to both OC and OS)
Trouble source
Compressor
Fan motor
Inverter
TH2
TH3
TH4
Thermistor
TH5
TH6
TH7
Power
Emergency operation pattern (2 outdoor units)
OC failure
pattern
Trouble
OC
Normal
OS
Cooling Permitted Permitted
Emergency
operation
Heating
Permitted Permitted
Maximum total capacity
of indoor units (Note 1)
(Note 1) If an attempt is made to put into operation a group of indoor units whose total capacity exceeds the maximum allowable capacity,
some of the indoor units will go into the same condition as Thermo-OFF.
HWE0716A
Error codes that permit an
emergency operation
0403
4220, 4225
4230
4240
4250, 4255
5110
5301
5102
5103
5104
5105
5106
5107
4102
4115
OS failure
pattern
Normal
Trouble
60%
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Error code description
Serial communication error
Bus voltage drop
Heatsink overheat protection
Overload protection
Overcurrent relay trip
Heatsink temperature sensor failure (THHS)
Current sensor/circuit failure
Subcool heat exchanger bypass outlet temperature sensor failure
Pipe temperature sensor failure
Discharge temperature sensor failure
Accumulator inlet temperature sensor failure
Subcool heat exchanger liquid outlet sensor failure
Outside air temperature sensor failure
Open phase
Power supply sync signal abnormality
GB