Mitsubishi Electric EHPT20Q-VM2EA Service Manual page 35

Indoor unit only operation
In indoor unit only operation, an operation without connecting outdoor unit is possible.
When in Indoor unit only operation the main control has control functions.
<Heater>
Heating for DHW and heating is provided by the booster heater.
Activating indoor unit only operation mode
To activate indoor unit only operation see the following:
1. Switch OFF the breaker for the indoor unit.
2. Change DIP switch SW4-4 and SW4-5 to ON.
3. Switch ON the breaker.
4. Indoor unit only operation is now activated.
To deactivate indoor unit only operation see the following:
1. Switch OFF the breaker for the indoor unit.
2. Change DIP switch SW4-4 and SW4-5 to OFF.
3. Switch ON the breaker.
4. Indoor unit only operation is now deactivated.
Emergency operation
In emergency operation, an operation without connecting outdoor unit and main remote controller is
possible.
When in Emergency operation the main control has NO control functions.
Heating flow temp. is restarted 40°C and DHW supply max.temp. is restricted 50°C. *1
<Heater>
Heating for DHW and space heating is provided by the booster heater.
Activating emergency operation mode
To activate emergency operation see the following:
1. Switch OFF the breaker for the indoor unit .
2. Change DIP switch SW4-5 to ON.
3. Switch ON the breaker.
4. Emergency operation is now activated.
To deactivate emergency operation see the following:
1. Switch OFF the breaker for the indoor unit .
2. Change DIP switch SW4-5 to OFF.
3. Switch ON the breaker.
4. Emergency operation is now deactivated.
WARNING
Do not attempt to change the DIP switches whilst the breaker are ON as this could result in
ELECTROCUTION.
GCH15010
Indoor unit
Heat pump
Main remote controller
DIP switch setting
Setting range for flow temp.
Setting range for tank temp.
Indoor unit
Heat pump
Main remote controller
DIP switch setting
Setting range for flow temp.
Setting range for tank temp.
*1 Default setting is 50°C. Once system has started running,
emergency operation runs at the latest set temp.
35
Indoor unit only operation
Necessary
Not necessary
Necessary
Electric heater
SW4-4 ON, SW4-5 ON
25 - 60°C Selectable
40 - 70°C Selectable
Emergency operation
Necessary
Not necessary
Not necessary
Electric heater
SW4-5 ON
Fixed at 40°C
Fixed at 55°C *1