Mitsubishi Electronics PUHY-P144 Manual De Usuario

[

VII  Control ] 

- 111 -

HWE08040

GB

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 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 for the temperature.

Heating operation 

Test run mode  

ON 

Thermostat ON 

Defrost  

operation 

3-minute restart  

prevention 

*Note 1,2 

*Note 1,2 

YES 

YES 

YES 

YES 

YES 

NO 

NO 

NO 

NO 

NO 

1. Indoor/outdoor unit fan control 
2. Inverter frequency control 
3. Indoor unit LEV, LEV1,LEV2a, LEV2b control 
4. Solenoid valve control 
5. 72C 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, LEV1 Fully closed 
     LEV2a, LEV2b rated opening 
4. All solenoid valves OFF 
5. Outdoor unit fan stop 
6. 72C OFF 
 

4-way valve OFF 

Stopping the  

defrost operation 

Stopping the defrost  
operation 

Return to heating  
operation 

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. LEV2a, LEV2b  fully opened. 
8. 72C control 

Unit in the stopped state