Gree HNTF24/A-D, Service Manual

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9
Condensing Unit
Service Manual
CONTROL
Cooling OFF Sub Mode Flowchart:
OFF signal is sent
out from wired
controller
Compressor
Outdoor fan
Object
Time
2.2 Dry Mode
Dry mode operation is as follows:
4-way valve Wire (O)
4-way valve Wire (B)
Compressor Control Wire
Indoor fan
Control Object
Time
ON(24V)
ON(24V)
OFF(OV)
(Low speed)
OFF(OV)
OFF(OV)
ON(24V)
ON(24V)O N(24V)
OFF(OV)
When Tambient≥Tset+2°C, the unit will start in cooling mode; In this case, the compressor starts and
indoor fan runs at set speed. After 20s, 4 way valve for cooling start running.
When Tambient≤Tset-2°C, the unit will stop during cooling operation; In this case, the compressor stops
and indoor fan runs at set speed. The 4-way valve for cooling remains original state.
When Tset-2°C<Tambient<Tset+2°C, the unit will operate in the state that the compressor starts 6min and
then stops 4min in cycle. In this case, indoor fan runs at low speed and the 4-way valve for cooling is always
running.
2.3 Fan Mode
(Vset)
ON
ON
OFF
Control objects
Other loads
Indoor fan
Time
Indoor fan will run at high speed for 5s and then at set speed. In this case, other loads stop.
3 CONTROLLER