TCM MMCUT18AS2, Service Manual, Page: 20 / 127

20
4) If the compressor cumulative running time
reaches 120 minutes and T3<-15
℃
.
Defrost Stop Conditions
If any one of the following conditions is satisfied,
defrosting ends and the unit returns to normal
heating mode:
----T3 rises above than TCDE1
℃
.
----T3 remains at TCDE2
℃
or above for 80
seconds.
----The machine runs for 10 consecutive minutes
in defrosting mode.
Defrosting Action
：
off on
Cool-F9
10S 30S
TimeA
10S
4-way valve defrosting Defrosting over
compressor
Indoor fan
Outdoor fan
EXV open
frequency
Max 10 minutes
frequency
Compressor stops
off
Anti-cold control
off
480P 480P for 240s
Condition of ending defrosting:
If any one of following items is satisfied,
defrosting will stop and the machine will turn to
normal heating mode.
①
T3 > TempQuitDefrost_ADD
℃
;.
②
The defrosting time achieves 10min.
③
Turn to other modes or off.
5.4.3 Outdoor Fan Control
5.4.3.1 Cooling Mode
Under normal operating conditions, the system
chooses the running fan speed according to the
ambient temperature:
Outdoor ℃
45
43
Supper high fan speed
28
26
High fan speed
25
23
Middle fan speed
22
20
Low fan speed
19
17
Supper low fan speed
10
9 Breeze fan speed
0
-1 F fan speed
-5
-6
G fan speed
-10
-11
H fan speed
I fan speed
When low ambient cooling is in effect::
Outdoor fan speed control logic (low ambient
cooling)
When T4
<
15
℃
(59
℉
) and T3 < 30
℃
(
86
℉
),
the unit enters into low ambient cooling mode.
The outdoor fan chooses a speed according to T3.
When T3
≥
38
℃
(100.4
℉
) or when T4
≥
20
℃
(
68
℉
), the outdoor fan chooses a speed
according to T4 again.
38
Exit low ambient cooling
mode
, run with high fan
for 1 minute
Low
30
27
23
off