Midea MSH-07CRN1, MSH-07HRN1, MSH-09CRN1, MSH-09HRN1, MSH-12CRN1, MSH-12HRN1 - Electronic Control Principle of Large Cooling Capacity Split Model A;C

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8. Electronic Control Principle of Large Cooling Capacity Split Model A/C
8.1 Fan only mode
Fan speed is high/mid/low/ Auto
8.2 Cooling mode
The 4-way valve is closed at cooling mode.
The action of the compressor and the outdoor fan:
T: Room temp.
Ts: Setting temp.
Condition Compressor Outdoor fan
T> Ts+1 On On Temp. up
T<Ts+1 Off Off
T> Ts On On Temp. down
T<Ts Off Off
Auto fan
Condition(T=Indoor Temp.-Setting Temp.) Indoor fan speed
T<1℃ Low
1<T<℃ 4℃ Med.
Temp. up
T>5℃ High
T> 4℃ High
1<T<℃ 4℃ Med.
Temp. down
T<1℃ Low
Anti-freezing control to indoor evaporator
Condition
Temp. Time
Compressor Outdoor fan
T> TE6 On On Temp. up
T< TE6 >4 Minutes Off Off
T> TE5 On On Temp. down
T< TE5 >4 Minutes Off Off
Condenser high temp. protection( only for heat pump)
Temp. Condition Compressor
T> TE10 Off Temp. up
T< TE10 On
T> TE11 Off Temp. down
T< TE11 On
8.3 Dehumidifying mode
8.3.1 Indoor fan speed at low speed.
8.3.2 Protection is same as cooling mode.
8.4 Heating mode
8.4.1 Generally, the 4-way valve is open in heating mode, but it is closed in defrosting mode.
8.4.2 Generally, the outdoor fan is turned off with the on-off action of compressor in heating mode, except
for the defrosting mode or the end of defrost.
8.4.3 Action conditions of compressor at heating mode: compressor must run for 4 minutes after starting
and then judge temperature. Meanwhile other protections are still valid.
Condition Compressor Outdoor fan
T> Ts+4 Off Off Room temp. up
T<Ts+4 On On
T< Ts+3 On On Room temp. down
T>Ts+3 Off Off