Midea MFJ-24ARN1-QB8 Technical & Service Manual page 20

7.3.3 Defrost (only available to heating mode)
7.3.3.1 Defrosting Conditions
Starting Of Defrosting Condition (meet one of the following is ok):
(1)Accumulated compressor operating time when temperature of outdoor heat exchanger coil
T3 is below -2° C reaches up to over 46 minutes.(When T3 is over 20° C, calculate time again.)
(2) Under evaporator high temperature protection, the accumulated time when outdoor fan
motor is off and compressor is on reaches up to over 90 minutes .(When T3 is over 20° C, calculate
time again.)
High temperature defrosting condition:
Under high temperature protection of evaporator, the time when outdoor fan is shut down but
compressor is not has been accumulated for up to 90 minutes.
7.3.3.2 Defrosting Action
Four-way valve, indoor fan, outdoor fan are shut down. Compressor keeps on.
7.3.3.3 Ending Of Defrosting Condition (meet one of the following is ok):
(1)Time of defrosting lasts 10 minutes.
(2)Temperature of outdoor coil T3 is up to 20° C.
7.3.4 Cooling Mode
7.3.4.1 Four-way valve is closed.
If four-way valve is open before the machine enters cooling mode, then four-way valve will be
closed at the first time, the compressor starts under the cooling mode.
7.3.4.2 Conditions for the compressor and outdoor fan action (Ts = set temperature)
Room temperature up
Room temperature down
7.3.4.3 Action of Indoor Fan
HIGH/LOW/AUTO fan can be switched over by your comfort.
Auto fan under cooling mode.
Room temperature up
Room temperature down
7.3.5 Dehumidifying Mode
7.3.5.1 Indoor fan speed is low.
7.3.5.2 If certain protective condition is met, operation will be carried out.
T2<20° C
Condition Compressor and outdoor fan
T1-Ts=0° C Off
T1-Ts>1° C On
T1-Ts>0° C On
T1-Ts=0° C Off
Condition
T1-Ts>2° C
1° C < T1-Ts <2° C
T1-Ts>1° C
T1-Ts <1° C
18
Electronic function
Off
Fan speed
Hi.
Low
Hi.
Low