Mitsubishi Electric R410A Service Handbook page 119

[5-3 Operation Flowcharts ]
(2) Heating operation
1. Indoor unit fan operation at
Very Low speed
2. Inverter output 0Hz
3. Indoor unit LEV, LEV1 Fully closed
LEV2 rated opening
4. All solenoid valves OFF
5. Outdoor unit fan stop
6. 72C OFF
1) When outdoor unit starts defrosting, it transmits defrost operations command to indoor unit, and the indoor unit start defrosting
operations. Similarly when defrosting operation stops, indoor unit returns to heating operation after receiving defrost end com-
mand of outdoor unit.
2) Defrost end condition: 12 minutes have passed since defrost operation started.
Outdoor unit pipe temperature: Refer to the following page(s).[5-2-7 Defrost Operation Control](page 97)
HWE14080
Heating operation
*Note 1,2
YES
Defrost
operation
NO
4-way valve ON
YES
Test run mode
ON
NO
NO
Thermostat ON
YES
YES
3-minute restart
prevention
NO
1. Indoor/outdoor unit fan control
2. Inverter frequency control
3. Indoor unit LEV, LEV1,LEV2 control
4. Solenoid valve control
5. 72C control
- 110 -
Normal operation
Defrost operation
Unit in the stopped state
During test run mode
4-way valve OFF
1. Indoor unit fan stops
2. Inverter defrost frequency control
3. Indoor unit LEV fully closed.
4. Solenoid valve control
5. Outdoor unit fan stop
6. LEV1 control
7. LEV2 fully opened.
8. 72C control
*Note 1,2
NO
Stopping the
defrost operation
YES
Stopping the defrost
operation
Return to heating
operation
GB