Floor Standing MFM    DM16-01.01.25en 
Service manual    36 
9.Electronic function 
9.1 Main data Introduction 
Ts : Set temperature,   
T1 : Room temperature 
T2: Evaporator pipe temperature   
T3: Condenser pipe temperature   
T4: Outdoor ambient temperature 
T5: Compressor discharge temperature 
 
9.2 Main Protection 
9.2.1 Time delay for the compressor start-up 
At the beginning of energizing or after the stop of the compressor, certain time delay will be needed 
to start the compressor. 
When switching over between cooling/heating/dehumidifying mode, the compressor stops 
automatically. 
9.2.2 Sensor protection at open circuit and breaking disconnection. 
9.2.3 Phase check function 
If the phase sequence is detected wrong or lack of 1 or 2 phase, the unit won’t start and there is 
error code displayed on outdoor PCB. 
 
9.3 Operat ionModesandFunctions
9.3.1 Heating Mode 
9.3.1.1 Four-way valve opens at once, while defrosting process closes. 
9.3.1.2 Compressor and outdoor fan running rules: 
Oncethecompressorstartsup,itwillfollowthebelowrules:
T1-TS
On
Off
 
When compressor is on, outdoor fan will follow the below rules:: 
For single-fan models: The outdoor fan runs all the time. 
For double-fan models: 
Fan(below): When compressor is on, the outdoor fan runs all the time. 
Fan(above):