MITSUBISHI ELECTRIC P500YMF-C - Manual (Page 56)

–54–
YES
YES
NO
YES
YES
NO
NO
NO
(5) Heating operation
Normal operations
Defrosting operations
Stop
Test run
1. Indoor unit fan very low speed
operations
2. Inverter output 0Hz
3. Indoor unit LEV, oil return LEV
fully closed
4. Solenoid valve OFF
5. Outdoor unit fan stop
6. BC controller solenoid valve
OFF
7. BC controller LEV fully closed
1. Indoor and outdoor unit fan
control
2. Inverter frequency control
3. Indoor unit LEV, oil return LEV
control
4. Solenoid valve control
5. BC controller solenoid valve
control
6. BC controller LEV control
1. Indoor unit fan stop
2. Inverter defrost frequency control
3. Indoor unit LEV fully opened, oil
return LEV fully closed
4. Solenoid valve control
5. Outdoor unit fan stop
6. BC controller solenoid valve control
7. BC controller LEV control
Heating operation
4-way valve ON
Defrosting
operation
Test run start
4-way valve OFF
Thermostat ON
3-minute
restart
prevention
Note : 1 When outdoor unit starts defrosting, it transmits defrost operations command to (BC controller and) indoor unit, and the
indoor unit starts defrosting operations.
Similarly when defrosting operation stops, indoor unit returns to heating operation after receiving defrost end command of
outdoor unit.
Note : 2 Defrosting start condition : After integrated 50 minutes of compressor operations, and –8˚C: or less outdoor unit coil
temperature. (TH7)
Defrosting end condition : After 12 minutes of defrosting operation or the outdoor unit coil temperature (TH5 and TH7)
having risen to 7˚C or more.
Note : 1
Note : 2