Emergency Operation Mode - Mitsubishi Electric PFD-P250 Service Handbook

[ III Control ]

-10- Emergency Operation Mode

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) When the error type displayed in 1 above allows the unit to run the emergency operation (as shown in the table
below), the retry operation will start automatically.
Pattern of Error
emergency source
operation
mode
At malfunc- Outdoor
tion of No.1 unit
(INV)
At malfunc-
tion of No.2
Thermistor
error
(2) Ending the emergency operation
1) End conditions
When one of the following conditions is met, emergency operation will end.
When an error is reset
*When resetting an error with the remote controller or the external input
When an error is detected that does not allow the unit to run the emergency operation.
(3) Miscellaneous
1) End conditions
When encountering problems other than the ones listed above, the system makes an error stop without performing
emergency operation. (Only the indoor fan operates unless problems are found with the fan.)
When problems are found in only one of the two units of a 2-refrigerant circuit, only the unit with the problems will run
an emergency operation or stop its operation, and the other unit will keep running its operation.
Emergency operation is intended only as a first aid until the unit is serviced. Have the unit serviced without delay to
restore a normal operation.
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
TH5
TH7
TH8
- 26 -
Type of error
that does not al-
low the unit to
go into the
emergency op-
eration
4230 All errors other
than the ones
4250 listed on the left
4240
4230
4260
4220
5301
4200
5110
0403
4108
5105
5107
5108
Operation
Emergency operation with only
No.2 compressor
Emergency operation with only
No.1 compressor