Emergency Operation; When Wireless Remote Controller Fails Or Its Battery Is Exhausted; When Wired Remote Controller Or Indoor Unit Microprocessor Fails - Mitsubishi Electric Mr.Slim PKA Series Service Manual

9-5. EMERGENCY OPERATION

9-5-1. When wireless remote controller fails or its battery is exhausted

9-5-2. When wired remote controller or indoor unit microprocessor fails

1. When the wired remote control or the indoor unit microprocessor has failed, but all other components work properly,
Setting the switch (SWE) on the indoor controller board ON will begin the indoor unit Emergency Operation.
When Emergency Operation is activated, the indoor unit operates as follows:
(1) Indoor fan is running at high speed. (2) Drain pump is working. (option)
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.
However, if the indoor unit microprocessor has failed, it is nesessary 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.
• 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.
OCH758
When the remote controller cannot be used
When the batteries of the remote controller run out or the remote
controller malfunctions, the emergency operation can be done using the
emergency buttons on the grille.
C D A STANDBY lamp
B OPERATING lamp
C Emergency operation cooling switch
D Emergency operation heating switch
E Receiver
Starting operation
• To operate the cooling mode, press the
B
• To operate the heating mode, press the
A
• Lighting of the OPERATING lamp B means the start of operation.
Note:
E
Details of emergency mode are as shown below.
Details of EMERGENCY MODE are as shown below.
Operation mode
Set temperature
Fan speed
Airflow direction
Stopping operation
• To stop operation, press the
24
button C for more than 2 seconds.
button D for more than 2 seconds.
COOL HEAT
24°C
High
Horizontal (Step 1) Downward (Step 5)
button C or the button D for more than 2 seconds.
24°C
High