Electronic Function; Main Protection - Midea MFM-24ARN1-Q Service Manual

Floor Standing MFM DM16-01.01.25en

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.
Operation Modes and Functions
9.3
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:
Once the compressor starts up, it will follow the below rules:
T1-TS
Off
On
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):
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