Continuous - Mitsubishi Electric PLA-A12BA Service Manual

10-5. EMERGENCY OPERATION
10-5-1. When wireless remote controller troubles or its battery is exhausted
10-5-2. When wired remote controller or indoor unit microcomputer troubles
1.When the wired remote control or the indoor unit microcomputer has failed, but all other components work properly,
if you set the switch (SWE) on the indoor controller board ON, the indoor unit will begin emergency operation.
When emergency operation is activated, the indoor unit operates as follows:
(1)Indoor fan is running at high speed. (2)Drain-up machine is working.
Note on the wireless remote control: when the remote control does not function, it is possible to activate
emergency operation by using the indoor unit emergency operation switch (SW1, SW2 of the wireless signal
receiver board).
However, if the indoor unit microcomputer has failed, it is necessary to proceed with points 2 and 3 below as in the
case of the wired remote control.
2.When you activate emergency operation of the cooling or heating, you have to set the switch (SWE) on the indoor
controller board and activate emergency operation of the outdoor unit.
For details on how to activate emergency operation of the outdoor unit, refer to the outdoor unit wiring diagram.
3.Before you activate emergency operation, check the following points:
(1)Emergency operation cannot be activated when:
•the outdoor unit malfunctions. •the indoor fan malfunctions.
•when it has detected the malfunction of drain-up machine during self-diagnosing.
(2)Emergency operation becomes continuous only by switching the power source on/off.
ON/OFF on the remote control or temperature control etc. does not function.
(3)Avoid operating for a long time when the outdoor unit begins defrosting while emergency operation
of the heating is activated because it will start to blow cold air.
(4)Emergency cooling should be limited to 10 hours maximum (The indoor unit heat exchanger may freeze).
(5)After emergency operation has been deactivated set the switches etc. to their original positions.
(6)Movement of the vanes does not work in emergency operation, therefore you have to slowly set them
manually to the appropriate position.
When the remote controller cannot be used
When the batteries of the remote controller run out or the remote control-
ler malfunctions, the emergency operation can be done using the emer-
gency buttons on the grille.
DEFROST/STAND BY lamp
Operation lamp
Emergency operation switch (heating)
Emergency operation switch (cooling)
Receiver
Starting operation
• To operate the cooling mode, press the
seconds .
• To operate the heating mode, press the
seconds .
* Lighting of the Operation lamp
Note:
• Details of emergency mode are as shown below.
Operation mode
Set temperature
Fan speed
Airflow direction
Stopping operation
• To stop operation, press the
26
for more than 2
button
for more than 2
button
means the start of operation.
COOL HEAT
24 ,75˚F 24 ,75˚F
High High
Horizontal Downward 5
button or the button .