Mitsubishi Electric CITY MULTI PUHY-400YMF-C Service Handbook page 67

(14) Operation Mode
1) Operating modes of the indoor unit
The following five modes can be set by the remote control.
1 Cooling mode
2 Heating mode
3 Dry mode
4 Fan mode
5 Stop mode
2) Operating modes of the outdoor unit
The following are the 3 modes for the outdoor unit.
1 Cooling mode
2 Heating mode
3 Stop mode
Note : If the outdoor unit has been in the cooling mode and the other indoor units (in stop, fan, thermostat off) are
set to the heating mode, those indoor units will not be operated and the heating indicator will be flashed
on the remote controller. The reverse also applies when the outdoor unit is operated in the heating mode
and the cooling indicator will be flashed on the remote controller.
(15) Emergency response operating mode
The emergency operation mode is a mode in which the unit is run in an emergency to respond to the trouble when the
compressors (No . 1, No. 2) break do wn, making it possib le to carr y out a abnor mality reset using the remote control.
1) Starting the Emergency Operation Mode
1 Trouble occurs (Display the abnormality code root and abnormality code on the remote control).
2 Carry out trouble reset with the remote control.
3 If the abnormality indicted in 1 above is of the kind that permits emergency operation (see the table below),
initiate a retry operation.
If the trouble indicated in 1 above is of the kind where emergency operation is impossible (see the table below),
restart operation after carrying out the previous abnormality reset (without entering the emergency operation
mode).
4 If the same abnormality is detected again during the retry operation in 3 above, carry out trouble reset once
more with the remote control, then try emergency operation starting corresponding to the contents of the
abnormality
Table Emergency Operation Mode Patterns and Abnormality Codes for which Emergency Operation is Possible or Impossible
Emergency Mode
Codes for which emergency operation is
Pattern
possible.
When a No. 1
Serial transmission trouble
Compressor Failure
VDC sensor/circuit trouble
Occurs
Bus voltage trouble
Radiator panel overheat
protection
Overload protection
IPM Alarm output/
Bus voltage trouble/
Over Current Protection
Cooling fan trouble
Thermal sensor trouble
(Radiator panel)
IAC sensor/circuit trouble
When No. 2
Overcurrent protection
Compressor Failure
Occurs
Caution
During emergency operation, only
In case, more than
would be on the stand-by mode.
No. 1 Compressor Failure
No. 2 Compressor Failure
All indoor units are operated in cooling mode
All indoor units are operated in heating mode
All indoor units are in fan or stop mode
marked percentage of indoor units can be operated during emergency operation.
marked percentage of indoor units are operated, over than the percentage of indoor units
400 500
48 % 65 %
65 % 65 %
Abnormality Codes for
which Emergency
Impossible
Operation is
0403
4200
4220 Trouble codes other than
those at left.
4230
4240
4250
4260
5110
5301
-64-
Action
Emergency Operation only with the
No. 2 Compressor
* After the retry operation, even if
there is a diff erent abnormality
code detected within <Inverter
Abnormality> at left, press the
button and after resetting, start
the unit by emergency operation.
[Example]
4250 Reset Retry
Reset Emergency
operation
Emergency Operation only with the
No. 1 Compressor
4240