Heating Mode; Defrosting - Gree FGR20/BNa-M Service Manual

Duct Type Split Air Conditioner
Service Manual

2.3 Heating Mode

When Tambient ≤ Tset-1℃ , the unit will run in heating mode. In this case, compressor and outdoor fan run;
Indoor fan runs at setting speed and under the condition of anti-cold air.
When Tambient ≥ Tset+1℃ ,compressor and outdoor fan stop running, the 4-way valve is still energized
and indoor fan runs under the condition of blowing residual heat.
When Tset -1℃＜ Tambient ＜ Tset+1℃ ,the unit will keep its previous running state.

2.4 Defrosting

Defrosting start condition: If the unit heats for 44min accumulatively, the compressor continuously runs for
4min and 50s, and T condensate ≤ -5℃ ,defrosting will start. If there is auxiliary heater, it will stop firstly and then
the 4-way valve, indoor fan and outdoor fan will stop in 10s and the compressor will compulsively run.
Defrosting end condition: If the unit defrosts for 10min or T condensate ≥ 10℃ , defrosting will end, 4-way
valve will start running, outdoor fan will run, and compressor compulsively run. Indoor fan will run under the anti-
cold air condition.
CONTROL
14
ON
OFF
Compressor
OFF
Outdoor fan
Indoor fan OFF
OFF
Auxiliary heater
OFF
4-way valve
1s 20s
Satrt defrostig
ON
Compressor
ON
Outdoor fan
ON
Indoor fan
ON
Auxiliary heater
ON
4-way valve
10s
Heating mode
Manually OFF
ON
OFF
ON
Blowing residual heat
Run under set
speed
ON
Running condition
is met
ON
OFF
ON
10s 15s
Anti-cold air
Defroting mode
End defrosting
ON
OFF
OFF
OFF
ON
OFF
1s
Anti cold air
OFF
OFF
OFF
Time
45s 60s
Run at set speed
ON
Running conditions
are met
ON
Time
10s