Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 168

-16- Emergency Operation Mode (P168-P234 models only) <PUHY/PURY>
When compressors (No.1 or No.2) fails, the unit goes into the emergency operation mode to respond to the problem. The
unit can be put into this mode by performing an error reset on 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) The unit will go into the mode that is appropriate to the error type.
Pattern of Error
emergency source
operation
mode
At malfunc- Outdoor
tion of No.1 unit
(INV)
At malfunc-
tion of No.2
(2) Ending the emergency operation
1) End conditions
When one of the following conditions is met, emergency operation will end.
When an integrated operation time of compressor in cooling mode has reached 5 hours.
When an integrated operation time of compressor in heating mode has reached 5 hours.
When an error is detected that does not allow the unit to run the emergency operation.
2) Control at the completion of and after the emergency operation
To end the operation, stop the compressor and bring up the error code on the display on the remote controller.
If another error reset is performed upon finishing an emergency operation, the unit will repeat the procedures 1)
through 3) under section (1) above.
To finish an emergency operation and to run a current-carrying operation after correcting the error, perform a power
reset.
Type of error that allows the unit to go
into the emergency operation
Heatsink thermistor
,<Inverter error>
Overcurrent break
Overload protection
Heatsink overheat protection
Cooling fan abnormality
Bus voltage drop protection
IDC sensor/circuit error
VDC sensor/circuit error
THHS sensor/circuit error
IPM communication error
Overcurrent protection
- 159 -
Type of error
that does not al-
low the unit to
go into the
emergency op-
eration
4230 All errors other Emergency operation with only
than the ones No.2 compressor
4250 listed on the left * After a retry operation, emer-
4240 gency operation can be re-
4230 sumed by error reset if the error
code that corresponds to the er-
4260 ror that is experienced is listed
4220 under <Inverter Error> on the
left, even if the error code does
5301 not match the original error
4200 code.
5110 4250 -> reset -> retry -> 4240
-> reset -> emergency opera-
0403 tion
4108 Emergency operation with only
No.1 compressor
[ VII Control ]
Operation