Airwell AWAU-YHD009-H11, Service Manual

Page: 30 / 62

CONTROL SYSTEM
SM HHD 1-A.1 GB 12-5
12.4 Heat Mode
For Model 09 and 12
If RAT≤SPT+2, the unit will operate in heating mode. The compressor, outdoor fan and 4-way valve
will operate and the indoor fan will delay 3min to start at the latest
If SPT+2≤RAT≤SPT+5,the unit will maintain the previous status.
If RAT≥SPT+5, the compressor will stop, the outdoor fan will delay 30s to stop and the indoor fan
will blow for 60s at the sett
ing speed. During this period, the fan speed can’t be switched.
For model 18 and 24
If RAT≤SPT+3.5, the unit will operate in heating mode. The compressor, outdoor fan and 4-way
valve will operate and the indoor fan will delay 3min to start at the latest
I
f SPT+3≤RAT≤SPT+5,the unit will maintain the previous status.
If RAT≥SPT+5, the compressor will stop, the outdoor fan will delay 30s to stop and the indoor fan
will blow for 60s at the setting speed. During this period, the fan speed can’t be switched.
12.4.1 Indoor Fan Control in Heat Mode
Indoor fan speed depends on the indoor coil temperature
Anti-cold air function
When starting the heating mode, anti-cold air function will be activated and indoor fan operates
according to following rules.
Case -1 RAT<24
o
C :
When ICT
≤40
o
C IFAN = Stop for 2 min and then switch to low speed
When ICT >40
o
C IFAN = Low for 1 min and then switch to set speed
When ICT >42
o
C IFAN swtich to set speed immediately.
Case -2 RAT
≥24
o
C :
When ICT
≤42
o
C IFAN = Low for 1 min and then switch to set speed
When ICT >42
o
C IFAN swtich to set speed immediately.
Residual heat blowing function
During heating, when the stopping condition for the compressor is reached, the compressor and the
outdoor fan motor stop running while the louver moves to position L. The indoor fan will stop after
running for 60s at setting speed.
12.5 Auto Cool/Heat Mode
In AUTO mode, the system selects the running mode (COOL/HEAT/FAN) automatically according
to the room temperature. The display shows the actual running mode and setting temperature.
There will be 30s delay for mode conversion.
1. When RAT
≥26
o
C, the cooling mode is selected. The set point temperature is 25
o
C.
2. When RAT
≤22
o
C, the unit runs in heating mode. The set point temperature is 20
o
C
3. When 23
o
C
≤RAT≤ 25
o
C, upon initial startup, the unit will enter auto mode and run in automatic
fan mode. If the other mode changes into auto mode, the previous running mode will remain.