Mitsubishi Electric PURY-P72 Service Handbook page 149

[VII Control]
-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 pennits 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 pennit an emergency operation (Applicable to both OC and OS)
Trouble source
Error codes that permit an
Error code description
emergency operation
0403 Serial communication error
4220.4225 Bus voltaoe drop
Compressor
4230 Heatsink overheat orotection
Fan motor
4240 Overload protection
Inverter
4250.4255
Overcurrent relav trip
5110 Heatsink temperature sensor failure (THHS)
5301 Current sensor/circuit failure
TH2 5102 Subcool heat exchanaer bypass outlet temoerature sensor failure
TH3 5103
Pipe temperature sensor failure
Thermistor
TH4 5104
Discharoe temoerature sensor failure
TH5 5105
Accumulator inlet temperature sensor failure
TH6
5106
Subcool heat exchanQer liquid outlet sensor failure
TH7
5107
Outside air temperature sensor failure
4102
Open phase
Power
Power supply sync signa! abnormality
4115
Emergency operation pattem (2 outdoor units)
OC failure OS failure
pattern pattern
OC
Trouble Normal
OS
Normal Trouble
Emergency Cooling Permitted Permitted
operation
Heating
Permitted Permitted
Maximum total capacity
60%
of indoor units (Note 1)
Note
I
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 Thenno-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 perfonn 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.
HWE0803A - 139-
GB