Midea mcd-24hrdn1, Service Manual

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Electrical Control Function
Electrical Control System 185
For other models:
-2
T1-Ts-
∆
T
-3
High
Low
-5
Medium
-4
1.3.3.4 Defrosting mode ：
For 12k models:
Condition of defrosting:
----T4
＞
0
℃
,
Defrosting starts when either of the following
①
&
②
:
①
The units run with T3
＜
3
℃
for 40 minutes and T3 keeps lower than TCDI
℃
for more than 3 minutes.
②
:The units run with T3
＜
3
℃
for 80 minutes and T3 keeps lower than (TCDI+2)
℃
for more than 3 minutes..
----T4
＜
0
℃
,
If
①
and
②
are satisfied, then the program judges if T2 has decreased more than 5
℃
.When T2 has
decreased more than 5
℃
, enter the defrosting mode.
----No matter what value of the T4 is and whether the T2 drops more than 5 ℃ or not, if the machine runs
with T3 ＜ 3 ℃ for more than 120 minutes and T3 keeps lower than (TCDI+4) ℃ for more than 3 minutes, the
machine will enter defrosting mode.
Condition of ending defrosting:
If any one of the following items is satisfied, the defrosting will finish and the machine will turn to normal
heating mode.
----T3 rises to be higher than TCDE1
℃
.
----T3 keeps to be higher than TCDE2
℃
for 80 seconds.
----The machine has run for 10 minutes in defrosting mode.
 Defrosting action
：