Air Conditioner Service Manual
Electronic controller
NOTES:
RT-------Room Temperature.
IPT------Indoor Pipe Temperature.
ST------indoor Setting Temperature.
OPT---Outdoor Pipe Temperature.
CRT---Compensated Room Temperature
1. Automatic mode
1) The initial RT determines A/C working mode and setting temperature (ST), the mode is
determined effective only once unless A/C shut-down then re-started. If from other modes
switches to automatic mode (including mode conversion after shutdown), it should be that the
compress stop more than 3 min then temperature judgment and automatic mode are conducted (it
can conduct immediately from fan mode switched to automatic, the indoor fan stops, three minutes
later the response is made and start up). Within 3 min, the output as: Showing the room
temperature, indoor fans starts (or anti-cold airflow), the outdoor fan stops;
2) With auto re-start controller, once being turned off or in case of an accidently power cut, the A/C is
able to retain and restore the original mode when being turned on or the power supply is resumed,
if the auto restart function activated. power-down after power-on; while if the auto restart function
isn’t activated, the A/C enters standby state.
Cooling-only
Mode
Initial RT
Initial ST
Cooling
RT≥26
℃
23
℃
Dry
26
℃＞
RT≥20
℃
7
℃
Ventilating
RT
＜
20
℃
－
Under automatic mode (including from automatic converted into Dry mode), when the temperature
UP or DOWN signals from the remote controller is received, the setting temperature ST adjusts
correspondingly to the current room temperature plus or minus 1
℃
, the automatic regulating
temperature range is ± 2
℃
.
2
．
Cooling mode
1) The control of the compressor
a. When RT
－
ST≥1
℃，
the compressor is running.
b. When RT
－
ST
＜－
1
℃，
the compressor is off.
c. When
－
1
℃
≤RT
－
ST
＜
1
℃
, the compressor keeps its original state.
2) Outdoor fan motor and the compressor run simultaneously (except for defrosting).
3) The control of indoor fan motor:
a. Indoor fan motor can operate by automatic, low, middle, and high airflow speed circularly.
b. Indoor fan motor automatic airflow speed control, it works as shown in Figure 1:
Hi
Mid
Lo
RT
－
ST
1
℃
2
℃
4
℃
Figure 1 Cooling automatic airflow
When the temperature change leads the fan speed variation, the switch can only be made orderly,
and every grade of air flow speed runs 1 minute at least.
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