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Mini VRF SYSTEM
Control Functions
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•
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3-2. Reverse Cycle Start Control
Reverse cycle start control is performed under the following conditions:
The outdoor unit starts in Heating mode after microcomputer initialization when the power was turned ON.
The outdoor unit starts in Heating mode after it was stopped for 1 hour or longer.
When the outdoor unit starts in Heating mode after having been stopped for a long period of time, this control first
operates the unit in Cooling mode to return refrigerant from the outdoor unit heat exchanger to the liquid tubing.
This prevents back-flow of the refrigerant liquid which had accumulated in the outdoor unit heat exchanger.
operates the unit in Cooling mode to return refrigerant from the outdoor unit heat exchanger to the liquid tubing.
This prevents back-flow of the refrigerant liquid which had accumulated in the outdoor unit heat exchanger.
3-3. Inter Systems Refrigerant Oil Recovery Control
3-3-1. Inter systems refrigerant oil recovery cycle
In both indoor unit Cooling mode and Heating mode, this control is performed in the cooling cycle after a certain
amount of time has passed.
amount of time has passed.
3-3-2. Start of inter systems refrigerant oil recovery control
3-3-3. Flow of inter systems refrigerant oil recovery control
This control is performed periodically after the total compressor operating time exceeds 150 minutes.
Simplified flow of inter systems refrigerant oil recovery control
Inter systems refrigerant oil recovery control follows this flow process:
3-4. Reverse cycle Defrost Control
3-4-1. Defrost control method
Defrost with this system is done by reverse cycle defrost.
3-4-2. Conditions for start of defrost
Defrost control is started when the “frost detection”conditions are met, and the “defrost mask time”has elapsed.
Control time
1 minute
Outdoor units
Operates at a compressor frequency of 46 Hz.
Electronic
control valve
control valve
All indoor units operate at a fixed pulse according to the indoor
unit capacity.
unit capacity.
Indoor
units
units
Fan
The fan operates at the set fan speed, is stopped, or operates at
“Lo” fan speed, according to the operation mode of the indoor unit.
“Lo” fan speed, according to the operation mode of the indoor unit.
Control time
3 minutes (stops once before and after control)
Outdoor units
Operates at a compressor frequency of 65 Hz.
However depending on the operating conditions, the frequency
may be lower than this value.
However depending on the operating conditions, the frequency
may be lower than this value.
Electronic
control valve
control valve
All indoor units operate at a fixed pulse according to the indoor
unit capacity.
unit capacity.
Indoor
units
units
Fan
The fan operates at the set fan speed, is stopped, or operates at
“Lo” fan speed, according to the operation mode of the indoor unit.
“Lo” fan speed, according to the operation mode of the indoor unit.
Normal
operation
1-minute
stop
Inter systems refrigerant oil
recovery control (3-minute)
recovery control (3-minute)
1-minute
stop
Normal
operation
3. Special Controls
SM830195-03_Mini VRF SYS.indb 9
SM830195-03_Mini VRF SYS.indb 9
2014/09/04 18:14:07
2014/09/04 18:14:07
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