TCL TAC-42CF, Service Manual, Page: 8 / 17

TCL Air Conditioner Service Manual
7
(5) Defrost
Defrosting of the outdoor heat exchange is controlled by the microprocessor with detection by the defrost
sensor.
Defrost starting conditions
When the conditions of a) or b) is satisfy, the defrosting operation starts.
a) Under the heating operation, the compressor cumulative operation time exceeds
4
0 minutes and the
temperature of the outdoor defrost sensor reads lower than － 6
℃
ｃｏｎｔｉｎｕｏｕｓｌｙ ｆｏｒ ３ｍｉｎｕｔｅｓ．
b) Under the heating operation, the compressor cumulative operation time exceeds
4
0 minutes, if the
indoor pipe temperature is lower than 32
℃ continuously for 3 minutes.
Note: If haven’t the outdoor pipe temperature sensor that use the condition b) to defrost, against
use the condition a).
Defrost terminating conditions
When the condition c) or d) is satisfy, the defrosting operation stops.
c) The outdoor
pipe temperature is higher than 20 ℃
.
d) The defrosting time exceeds 10 minutes.
Defrosting time chart
Outdoor Fan ON OFF ON
Rever
s
ing Valve ON OFF ON
Compressor Relay ON OFF ON OFF ON
39S 5S Defrost Count MAX 12min 19S 15S t
(6) Assistant Thermistor Function
Assistant thermistor is add the thermitor of the electricity to rise the heating capacity automatically not
effected by the signal of the remote controller about assistant thermistor ON/OFF buttons.
1) When the condition all of A~G are satisfy, the assistant thermistor should be on .
A. Under the heating operation, the compressor has been running over than 2 minutes.
B. The indoor fan operates in normal.
C. The system operates not in defrosting.
D. The assistant thermistor
has been off over than 1 0 seconds.
E. The set ted temperature is 3 ℃ higher
than the room temperature
and 15ºC<T1<25ºC.
F. The room temperature is lower than 15 ℃
.
G.
The indoor pipe temperature
is lower than
4
5 ℃
.
2) When one of the conditions of A~E is satisfy, the assistant thermistor is off.
A. The compressor is off.
B.
The room temperature
higher than
2
5 ℃
.
C.
The indoor pipe temperature
is higher than 50 ℃
.
D.
The indoor fan is stopped.
6. “FAN” mode operation