Mitsubishi Electronics P240Y(T)SHMU-A Air Conditioner User Manual


 
[ VII Control ]
- 139 -
HWE0803A GB
-11- Emergency Operation Mode
1. Problems with the outdoor unit
The P144 through P240 models of unit have a mode that allows the outdoor unit to perform an emergency operation when
the other outdoor unit in the system malfunctions.
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)
Emergency operation pattern (2 outdoor units)
1) If an attempt is made to put into operation a group of indoor units whose total capacity exceeds the maximum allowable ca-
pacity, some of the indoor units will go into the same condition as Thermo-OFF.
(2) Ending the emergency operation
1) End conditions
When one of the following conditions is met, emergency operation stops, and the unit makes an error stop.
When the integrated operation time of compressor in cooling mode has reached four hours.
When the integrated operation time of compressor in heating mode has reached two hours.
When an error is detected that does not permit the unit to perform an emergency operation.
2) Control at or after the completion of emergency operation
At or after the completion of emergency operation, the compressor stops, and the error code reappears on the remote con-
troller.
If another error reset is performed at the completion of an emergency mode, the unit repeats the procedures in section (1)
above.
To stop the emergency mode and perform a current-carrying operation after correcting the error, perform a power reset.
Trouble source
Error codes that permit an
emergency operation
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
0403
4220, 4225
4230
4240
4250, 4255
5110
5301
5102
5103
5104
5105
5106
5107
4102
4115
Compressor
Fan motor
Inverter
Thermistor
Power
TH2
TH3
TH4
TH5
TH6
TH7
OC
OC failure
pattern
Trouble
Normal
Permitted Permitted
Permitted Permitted
60%
Cooling
Heating
Normal
Trouble
OS failure
pattern
OS
Emergency
operation
Maximum total capacity
of indoor units (Note 1)