Gree GWH09MA-K3NNA3F Service Manual page 28

Function and Control
② Protection
◆ Antifreezing protection
During drying and cooling operation, if the system is under antifreezing protection, the compressor and outdoor fan stop
operation while indoor fan operates at low speed. If antifreezing protection is eliminated and the compressor has been
stopped for 3 minutes, the complete unit will resumes its previous operation status.
During the cycle stage of operating 6 minutes and stopping 4 minutes, if antifreezing protection is detected, the compressor
and the outdoor fan will stop operation and the indoor fan will operate at low speed. When the antifreezing protection is
eliminated and the compressor has been stopped for 4 minutes, the complete unit will resume its previous operation state.
③ Other protection
Other protections are the same as those in cooling mode.
(3)Heating mode (not available for cooling only type)
①Heating conditions and process
When Tamb. ≤Tpreset+2℃, the unit starts heating operation. In this case, the 4-way valve, compressor and outdoor fan
operate simultaneously. The indoor fan operates after 2 minutes at most.
When Tamb≥Tpreset+4℃, the compressor and outdoor fan stop operation. The 4-way valve remains energizing and the
indoor fan will stop operation after operate at setting fan speed for 60s.
When T +2℃＜T
preset
In this mode, the 4-way valve is energizing. The temperature setting range is 16～30℃ and the indoor unit displays
operation icon, heating icon and set temperature.
②Defrosting Conditions and Process
With intelligent defrosting function, the unit can automatically defrost according to the actual condition. The indoor unit
displays "H1".
Tamb
Tpreset +2 ˚C
Tpreset –2 ˚C
Compressor
Outdoor fan
Indoor fan
＜ T +4℃, the unit will maintain its previous operation status.
amb. preset
6 min. 6 min.
4 min. 4 min.
low speed
Run Stop
Cooling
Drying
Stop running
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