Midea MSV1-09HRFN1-MT0W Service Manual page 29

8.7.4 Outdoor unit current control in heating mode.
Remark:
9K Model
12K Model
8.7.5 Indoor heat exchanger high temperature protection.
If T2＞60℃, the compressor will stop and not resume until T2＜48℃.
8.7.6 Defrosting mode.
1) Condition of defrosting.
Condition 1: If T4＞0℃,
When the units are running, if the following two items are satisfied the units start defrosting:
3 minutes.
3 minutes.
Condition 2: If T4＜0℃,
The program judges according to the condition 1, if the two items are satisfied, then judges if T2
has descended for more than 5℃, if it has the machine starts defrosting, or continues to judge T2
and will not defrost until T2 drops more than 5℃.
Condition 3: No matter what value T4 is, if the machine runs with T3＜3℃ for more than 120 minutes and T3
keeps lower than -2℃ for more than 3 minutes, the machine will defrost, no matter if T2 drops for
more than 5℃ or not.
2) Condition of ending defrosting.
If any one of following items is satisfied, defrosting will finish and the machine will turn to normal heating
mode.
I3HEAT
I2HEAT
I1HEAT
I1HEAT
5.2 A
5.2 A
a) The units runs with T3＜3℃ for 40 minutes and T3 keeps lower than -6℃ for more than
b) The units runs with T3＜3℃ for 80 minutes and T3 keeps lower than -4℃ for more than
comp. pause
freq. descends if curr. rises;
freq. remains if curr. descends
running normally
I2 HEAT I3 HEAT
7.0 A
7.0 A
8.0A
8.0 A
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