Midea MSV1-09HRDN1-QC2, Service Manual

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9.7.6 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:
a) The units runs with T3
＜
3
℃
for 40 minutes and T3 keeps lower than -6
℃
for more than
3 minutes.
b) The units runs with T3
＜
3
℃
for 80 minutes and T3 keeps lower than -4
℃
for more than
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.
a) T3 rises to be higher than 12
℃
.
b) T3 rises to be higher than 8
℃
and remains for 80 seconds.
c) The machine has run for 10 minutes in defrosting.
9.7.7 Defrosting action.
9.7.8 Rating capacity test function.
1) Set the indoor unit with remote controller as: high fan, 30
℃
in heating mode, then press “TURBO”
button on controller 6 times or more within 10 seconds(make sure indoor unit receives these signals), the
machine will turn into rating capacity test mode, the buzzer will make a “di” sound for 2 seconds
continuously. Also, indoor fan will change to rating speed, the frequency of compressor will be fixed as
on
off
on
off
on
off
on
off
compressor
4-way valve
outdoor fan
indoor fan
indoor fan breeze 10s
60s
70s
no longer than 10 minutes 30s
F8