Mitsubishi Electronics P120Y(T)HMU-A Air Conditioner User Manual


 
[ VII Control ]
- 150 -
HWE0803A GB
(2) Heating operation
*Note 1. When the outdoor unit goes into the defrost mode, defrost command is sent to the BC controller and indoor units.
Upon reception of the command, the indoor units will go into the defrost mode. When defrosting is completed and
upon receiving the signal that indicates the completion of defrosting, indoor units will resume the heating operation.
*Note 2. Defrost end condition: 10 or more minutes must pass after defrost operation.
or Outdoor unit piping temperature : refer to "-7-. Defrost operation control" of [2] Controlling the Outdoor
Unit.
Heating operation
Test run mode
ON
Thermostat
ON
Defrost
operation
3-minute restart
prevention
*Note 1,2
*Note 1,2
YES
YES
YES
YES
NO
NO
NO
NO
NO
1. Indoor/outdoor unit fan control
2. Inverter frequency control
3. Indoor unit LEV fully open
4. Solenoid valve control
5. BC controller solenoid valve control
6. BC controller LEV control
Normal operation
Defrost operation
4-way valve ON
During test run mode
1. Indoor unit fan operation at
Very Low speed
2. Inverter output 0Hz
3. Indoor unit LEV fully open
4. Solenoid valve OFF
5. Outdoor unit fan stop
6. BC controller solenoid valve control
7. BC controller LEV control
Stopping the
defrost operation
1. Indoor unit fan stop
2. Inverter defrost frequency control
3. Indoor unit LEV fully open
4. Solenoid valve control
5. Outdoor unit fan stop
6. BC controller solenoid valve control
7. BC controller LEV control
4-way valve OFF
1 3
Stopping the defrost operation
Unit in the stopped state