Electronic Function; Main Data Introduction; Main Protection - Midea MFE-60ARN1-RB4W Service Manual

8. Electronic function

8.1 Main data introduction

Ts : Set temperature,
T1 : Room temperature
T2: Evaporator pipe temperature
T3: Condenser pipe temperature
T4: Outdoor ambient temperature

8.2 Main Protection

8.2.1 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 st
ops automatically.
8.2.2 Sensor protection at open circuit and breaking disconnection.
8.2.3 Phase check function
If the phase sequence is detected wrong or lack of 1 or 2 phase, the unit won't st
art and there is error code displayed on outdoor PCB.
8.2.4 Over-current protection
When compressor is running, if the current is over twice of the rated for 3 seconds, the
compressor will stop and an error code will be displayed on the outdoor PCB. If the
current becomes normal for 3 minutes, the indoor sends signal to the outdoor, the outdoor
will display normally.
8.2.5 Outdoor protection
When outdoor protection signal is high level, outdoor unit will perform protection: the
whole machine will be shut down while the indoor unit will indicate the correspondi
ng protection signal.
The A/C will recover if outdoor protection signal is low level.
8.2.6 Air outlet of indoor unit high temperature protection
When the temperature of air outlet of indoor unit is up to 70° C, protection
signal is high level, then the unit will perform protection: electric heaters will be shu
t down at once, indoor fan speed will be high and four-way valve, compressor and
outdoor fan are shut down.
The A/C will recover if the temperature of air outlet of indoor unit is down to 55° C.
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