10
Technical Information
Service Manual
5) System high-pressure protection
a. When the high-pressure switch detects the system pressure higher than limit ,then the high-pressure switch cuts off, the system will stop
to run.
b.If high-pressure protection is detected for two times within one hour, only by cutting off the power and then reenergize that the compressor
can restart.
6) Compressor overload protection
No matter the compressor is on or off, when the compressor overload switch is detected activated, the system will stop and indoor unit
will display H3. If the compressor overload protection appears for more than 6 times, in this case, only by cutting off the power and then
reenergize that the compressor can restart. If the running duration of the compressor is longer than 30min, the protection times will be
cleared to zero.
7) Antifreeze protection
Under cooling and dry mode, 6minutes after the compressor is started:
When it is detected for 3 minutes successively that Tevap. Is less than -2
O
C(varying with indoor unit), the antifreeze protection will be
activated, in which case the outdoor unit will immediately shut off the indoor electronic expansion valve and the capacity will be set to “0”.
If Tevap. exceed 13
O
C and the compressor has remained at OFF for at least 3minutes, the compressor will resume its original operation
state.
8) IPM Protection
a. When the IPM module protection is detected, the unit will stop as the indoor temperature reaching set temperature, PFC is closed,
display IPM protection malfunction. After the compressor stops for 3min, the unit will resume operation status automatically; if the IPM
protection is detected for more than 6 times continuously (If the running time of the compressor is longer than 10min, the protection times
record will be cleared), the system will stop and send the signal of module protection to indoor unit. The unit can not resume operation
status automatically, but can resume running only after cutting off the power and then putting through the power.
b. IPM module overheating protection
(a) When TIPM
＞
88
O
C, prohibit to raise frequency;
(b) When 88
O
C
＜
TIPM
＜
95
O
C, the operation frequency of compressor lows down 1HZ/1s;
(c) When TIPM
＞
100
O
C, the compressor stops. After the compressor stops for 3min, if TIPM
＜
77
O
C, the compressor and the outdoor fan
will resume operation.
9) DRED function
If the power of DRED device is supplied by switching power supply, when different DRED signals are received, the corresponding
optocouplers are put through to make the AD sample circuit on the main board detect the different voltages. Different voltages are
corresponding to different DRED modes. After entering DRED mode, the indoor unit displays the corresponding operation code of DRED
mode.
d1: Outdoor compressor stops;
d2: The electricity consumption of complete unit in 30min is less than or equals to 50% of rated electricity consumption;
d3: The electricity consumption of complete unit in 30min is less than or equals to 75% of rated electricity consumption
