Mitsubishi PK18FL3 User Manual page 28

2-6 Emergency operation
When the remote controller or microprocessor malfunctions but all other parts are normal, emergency operation is started
by setting the dip switch SW3 on the indoor controller board.
<Before emergency operation>
1. Make sure the compressor and the indoor fan are operating normally.
2. Locate the defect with the self-diagnostic function. When the self-diagnostic function indicates "protective function is
working", release the protective function before starting the emergency operation.
CAUTION: When the self-diagnostic function indicates a check code of "P5" (drain pump malfunction), DO NOT start
the emergency operation because the drain may overflow.
<How to operate>
1. For emergency cooling, set the dip switch SW3-1 to ON and SW3-2 to OFF.
Emergency
cooling
2. Turn ON the outdoor unit breaker and then ON the indoor unit breaker.
Emergency operation will now start.
3. During emergency operation, the indoor fan operates on high speed, the auto vanes do not operate.
4. To stop emergency operation, turn OFF the indoor unit breaker.
5. Movements of the vanes do not work in emergency operation, therefore you have to slowly set them manually to the
appropriate position.
NOTE: The remote controller POWER ON/OFF button can not start/stop emergency operations.
CAUTION: Do not use emergency cooling for more than 10 hours, as the indoor coil may freeze.
Normal
operation
2 2
1 1
1 ON 1.2 OFF
SW3
Indoor controller board
OC275-28