Haier AW09EH2VHD Service Manual page 25

3. Compressor Ov O er-current Protection
If the current draw of the compressor at start-up is greater
than the values listed on the chart below for
seconds, the compressor will stop. After 3 minutes the
compressor will restart. If the over-current condition occurs
3 times in 20 minutes, the system will lock-out, and a code
will be indicated at the outdoor unit. It will be necessary to
remove power to the system to reset the lock-out condi-
tion.
Current Overload Prodection
Holds Decrease
Model
value 1Hz/10s
09K 8A
12K 13A
18K 15A 15A
4. Anti-freeze Protection of the Indoor Coil
The temperature sensed by the coil sensor is used to dete-
rmine at what speed the compressor is to run to avoid the
coil temperature being too cold.
Tpg_indoor: indoor unit pipe sensor tempe T T
Ts: outdoor unit Suction Line sensor temperature
When Min(Tpg_indoor , Tpg_indoor+Ts)/2) < Tpg1, the freq-
uency of the compressor decreases at the rate of 1HZ / 1
second.
When Min(Tpg_indoor , Tpg_indoor+Ts)/2) < Tpg2, the freq-
uency of the compressor decreases at the rate of 1HZ / 10
second.
When Tpg_indoor begins T T to rise again, and T T T
ndoor , Tpg_indoor+Ts)/2)
compressor does not change.
When Tpg3 < T T Min(Tpg_indoor , Tpg_indoor+Ts)/2) <Tpg4, the
frequency of the compressor increases at the rate of 1HZ / 10
second
Example: if Min(Tpg_indoor , Tpg_indoor+Ts)/2)
ains f 2 minutes, the outdoorunit will stop and indicate an ains f ains for
underload malfunction code at the outdoor unit. The com-
pressor stops for a minimum of 3 minutes. When Min(Tpg_
indoor , Tpg_indoor+Ts)/2)>Tpg4, the compressor will
restart
f f approximately 3
Decrease Over-current
1Hz/s point
12A 12A
9A 10A 10A
16A 16A
14A 15A
18A
16A 17A
rature
Min(Tpg_i-
Tpg3, the frequency of T T the
32°F sust-
SEQUENCE of OPERATION
Tpg4=48°F Increasing slowly
Tpg3=45°F
Tpg2=41°F
Tpg1=37°F
32°F
Stop
5. Base Pan Heater
To keep condensate water from freezing inside the cabinet,
a base pan heater is installed at the factory. Refer to the
chart below for the operating parameters.
Pan Heater Logic
Outdoor Temperature
37 /3
28 /-2 to 34 /1
10 /-12 to 25 /-4
10 /-12
52°F // / /
48°F // / /
Keeping the frequency
43°F
Decreasing slowly
Decreasing rapidly
Pan Heater
OFF
OFF 20min ON 10min
OFF 15min ON 15min
ON
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