Airwell YUDE024, Service Manual

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CONTROL SYSTEM
11-4 SM YUDE 2-A.1 GB
If HPS2 is cut off (Pressure higher than 3.0Mpa), the OFAN will go to high fan speed. If the HPS2
is recovery (pressure is 2.4MPa), the OFAN speed will reduce by 1 speed until the pressure is
reaching 3.0MPa.
This control is performed every 1 hour or pressure is below 2.4MPa.
11.1.5.4 OFAN control in heating mode:
OFAN will keep high fan speed
11.1.6 Refrigerant control
11.1.6.1 EEV is used for all model
1. EEV operation after power-on: When power on, EEV will open 240steps and then move back
with 540steps. This position will be recognized as 0. Then EEV will open to 480 steps and be
ready for system operating.
2. EEV openloop depends on OAT,RAT,SPT and compressor frequency after compressor starts
to operate.
3. Target CTT control will be performed after compressor operates for 5min.
4. The EEV opening will be updated every 5s.
11.1.7 Reversing Valve (RV) Control
Reversing valve is on in heat mode.
RV ON will delay 10 sec when compressor is ON and Switching of RV state is done only after
compressor is off for over 2 minutes.
11.2 Fan Mode
In this mode, the indoor fan may run at high,medium,low and automatic speed. The compressor,
outdoor fan and 4-way valve will be OFF.
In this mode, the range of setting temperature is 16~30C
11.3 Cool Mode
If Load>0, the unit starts cooling operation. In this case, the compressor and outdoor fan will
operate and the indoor fan will run at the setting speed.
If Load≤0, the compressor will stop operation and the outdoor fan will delay 60 seconds to stop.
While the indoor fan will run at the setting speed.