Main Logic; Control Function Of Outdoor Unit - Gree SUPER+ MULTI ULTRA Series Service Manual

Super Free Match
Service Manual

2 MAIN LOGIC

2.1 Control Function of Outdoor Unit

2.1.1 Cooling Mode
1) Cooling conditions and process:
If the compressor is in stop status and start the unit for cooling operation, when one of the indoor units
reaches the cooling operation condition, the unit starts cooling operation; in this case, the electronic expansion
valve, the outdoor fan and the compressor start operation.
2) Stop in cooling operation
a) Compressor stops
The compressor stops gradually, the outdoor fan stops after 1 min.
b) Some of the indoor units reach the stop condition (the compressor does not stop)
The compressor operates according to the required frequency. For the indoor unit with no requirement, the
corresponding electronic expansion valve is closed to 0P.
3) Cooling mode transfers to heating mode
When the unit transfers to heating mode, the 4-way valve is energized after the compressor runs for 40s. The
other disposals are the same as stopping in cooling mode.
4) 4-way valve:
In this mode, the 4-way valve is closed.
5) Outdoor fan control in cooling mode
The outdoor fan starts before 5s of the starting of compressor. The outdoor fan will run in high speed for 40s
after starting and then it will run in set speed.
The fan shall run at every speed for at least 80s. (When the quantity of indoor unit changes, the control part
will adjust the outdoor fan according to the quantity of indoor unit and outdoor temperature.); when the
compressor stops, the outdoor fan runs at present speed and stops after 1 min.
2.1.2 Dry Mode
1) The dry conditions and process are the same as those in cooling mode;
2) The status of 4-way valve: closed;
3) The temperature setting range: 16 ~ 30℃;
4) Protection function: the same as those in cooling mode;
5) In dry mode, the maximum value A of the capacity requirement percentage of single unit is 90% of that
in cooling mode. The open condition of the electronic expansion valve, outdoor fan and compressor is
the same as those in cooling mode.
2.1.3 Heating Mode
1) Heating conditions and process: When one of the indoor units reaches the heating operation condition,
the unit starts heating operation.
2) Stop in heating operation:
a) When all the indoor units reach the stop condition, the compressor stops and the outdoor fan stops after 1
min;
b) Some of the indoor units reach the stop condition. The compressor reduces the frequency immediately and
operates according to the required frequency;
c) Heating mode transfers to cooling mode (dry mode), fan mode:
The compressor stops;
The outdoor fan stops after 1min;
CONTROL 22