Compressor Overcurrent Protection; 4. Anti-Freeze Protection Of The Indoor Heat Exchanger - Haier HSU09VHG(DB)-W Service Manual

temperature-preventing protection of the indoor heat exchanger; if the temperature of the indoor heat
exchanger is lower than 47 , recover to the normal control.
TC
Fgh_t1 2
Fgh_t2 2
Fgh_t3 2
Fgh_t4—2
Fgh_t5—2
Normal
N Decreasing at the speed of 1HZ/1 second
P Decreasing at the speed of 1Hz/10 seconds
Q Continue to keep the last-time instruction cycle
R Increasing at the speed of 1Hz/10seconds
Remarks: the outdoor unit
5.2.5.3 The control of preventing the overcurrent of the compressor

3. Compressor overcurrent protection

During the starting process of the compressor, if the curren of the compressor is greater than 17A
for 3 seconds, stop the compressor and alarm, after 3 minutes, start it again, if such state appears 3
If the current draw of the compressor at start-up is greater
times in 20 minutes, stop the compressor and alarm, and confirm the malfunction. Then continue to
than the overcurrent point listed on the chart below for ap-
run it only after the the power is off.
proximately 3 seconds, the compressor will stop, and a code
During the starting process of the compressor, if the AC current is greater than 12A, the frequency
of the compressor decreases at the speed of 1HZ/second.
will be indicated at the outdoor unit. After 3 minutes the
During the starting process of the compressor, if the AC current is greater than 10A, the frequency
compressor will try to restart. If the overcurrent condition
of the compressor decreases at the speed of 0.1HZ/second.
occurs 3 times in 20 minutes, the system will lock-out, and a During the starting process of the compressor, if the AC current is greater than 9A, the frequency of
the compressor increases at the prohibited speed.
code will be indicated at the outdoor unit. It will be necessary
During the starting process of the compressor, if the AC current is greater than 8A, the frequency of
to remove power to the system to reset the lock-out condi-
the compressor increases at the speed of no faster than 0.1HZ/second.
tion.
The frequency of the compressor may change depending on
the current draw at start-up. Refer to the chart and current/
Hz table shown below.
Greater than current 1: Decreases 1Hz/second
Greater than current 2: Decreases 0.1Hz/second
Greater than current 3: No change
Over
Model current
Point
09K ~11A
12K ~13A
18K ~15A
24K ~17A

4. Anti-freeze protection of the indoor heat exchanger

The temperature sensed by the indoor unit tube sensor is
used to determine what frequency the compressor is to run
at for freeze protection.
Tpg_indoor: indoor unit pipe sensor temperature
When Tpg_indoor < Tpg1, the frequency of the compressor
decreases at the rate of 1HZ / 1 second.
When Tpg_indoor < Tpg2, the frequency of the compressor
decreases at the rate of 10HZ / 10 seconds.
When Tpg_indoor begins to rise again, and Tpg2 ≤ Tpg_indoor
≤ Tpg3, the frequency of the compressor does not change.
When Tpg3 < Tpg_indoor <Tpg4, the frequency of the com-
pressor increases at the rate of 1HZ / 10 seconds.
Example: if Tpg_indoor ≤ 32°F sustains for 2 minutes, the
outdoor unit will stop and indicate an underload malfunction
code at the outdoor unit. The compressor stops for a mini-
mum of 3 minutes. When Tpg_indoor >Tpg4, the compressor
will restart.
The compressor stops Fgh_t1 65
N Decreasing the frequency rapidly Fgh_t2 59
P Decreasing the frequency slowly Fgh_t3
Q Prohibiting increasing the frequency Fgh_t4
R Increasing slowly Fgh_t5
25
Domestic Air Conditioner
Decline Decline
Speed Speed
Current 1 Current 2 Current 3
~8.5A ~8A
~10A ~9.5A
~12A ~11.5A
~13.5A ~13A
SEQUENCE OF OPERATION
149°F
138°F
48°F
131°F
55
124°F
51
43°F
117°F 47
41°F
37°F
32°F
Decline
Speed
~7A
~8.5A
~10.5A
~12A
59°F // ice_temp_3+5
Increasing slowly
46°F // ice_temp_3+2
Keeping the frequency
43°F
Decreasing slowly
Decreasing rapidly ice_temp_1
Stop
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