Haier HBU-18CF03 Service Manual page 66

blowing fan runs at setting wind speed. This working area is defined as area A.
(2) Ts Tr Ts + 2 , the compressor and outdoor blowing fan run for 10 minutes then
pause for 6 minutes, while indoor blowing fan runs at low wind speed. This working
area is defined as area B.
(3) Tr < Ts, the compressor and outdoor blowing fan stop working while outdoor blowing
fan runs at low wind speed. This working area is defined as area C.
a. After dehumidifying program starting, the system converts between A, B and C areas
according to variations of room temperature with running mode being shown as the chart
below:
(4) Cutoff protection against overload and overheat
During heating program, if the indoor blowing fan has been started and the compressor
has been running more than 2 minutes, and the temperature of indoor coil pipe (Ticp)
> 64 , the outdoor blowing fan will stops running; If Ticp ≤ 50
blowing fan has kept stop state for 45 seconds, then it will restore rotation; If Ticp > 67
and such temperature has last for 10 seconds, the compressor will stop running and
indoor blowing fan run according to conditions as it reaches setting temperature. When
Ticp < 58 , and the compressor has kept stop state over 3 minutes, then the
compressor and outdoor blowing fan will restore normal running.
Cutoff protection for heating current
After 60 seconds from the compressor being started, if CT current exceeds I1 (9.2A) and
such case has kept 5 seconds, the outdoor blowing fan will stop. If 45 seconds has passed
after the outdoor blowing stops and the current of the compressor is less than I2 (7.5A), the
blowing fan will restore running. If CT current exceeds I3 (14.3A) and such case lasts for 3
seconds, the compressor and outdoor blowing fan will stop. The compressor will not restore
running until 3 minutes passes with CT current less than 12A.
(5) Cool wind prevention during heating program
At the first time entering heating program or after ending the latest frost removal, if the
temperature of indoor coil pipe (Ticp) < 28 , the indoor blowing fan will stop running; If
28 Ticp < 38 , the indoor blowing fan will run at low speed; If Ticp > 38
compressor has been running for more than 4 minutes, the indoor blowing fan will run at
66
Commercial Air Conditioner
Area A
Ts 1
Area B
Ts 1
Area C
Model: HBU-18CF03
HDU-42CF03/H HPU-42HF03
Area A
Ts 3
Area B
Ts
Area C
and the outdoor
or the