Emergency Operation Mode - Mitsubishi Electric PUHY-P250YNW-A Service Handbook

[5-2 Outdoor Unit Control ]
5-2-13

Emergency Operation Mode

1. Problems with the outdoor unit
Emergency operation mode is a mode in which outdoor units that are operating normally take over the operation of the out-
door units that are experiencing problems. (P500YSNW model goes into an emergency operation mode when one outdoor
unit is in trouble.)
This mode can be started automatically.
(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) Only the outdoor units that has not detected any errors will stay in operation.
3) If a TH2, TH3, TH5, or TH6 fault is detected, the sensor reading is complemented, and the unit will stay in operation.
4) If another thermistor fault is detected during the above-mentioned operation, the unit will make an abnormal stop.
Error codes that permit an emergency operation (Applicable to both OC and OS)
Trouble source
Compressor
Fan motor
Inverter
Thermistor TH2
TH3
TH4
TH5
TH6
TH7
TH15
Power
Emergency operation pattern (2 outdoor units)
Pattern
OC failure pattern
OS failure pattern
14
- chapter 5
Error codes that permit an
emergency operation
0403
4220,4225,4226
4230,4235
4240,4245
4250,4255,4256
5110
5120
5301
5305,5306
5102
5103
5104
5105
5106
5107
5115
4102
4115
OC status OS status
Trouble Normal
Normal Trouble
Error code description
Serial communication error
Bus voltage drop
Heatsink overheat protection
Overload protection
Overcurrent relay trip
Heatsink temperature sensor failure (THHS)
DCL temperature sensor circuit fault
Current sensor/circuit failure
Position error
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
Compressor shell bottom temperature sensor fault
Open phase
Power supply sync signal abnormality
Emergency operation Cooling capacity
Permitted 50%
BS_05_C