Basic Control; Normal Operation; Compressor Pi Control - Daikin RMXS-L Series Service Manual

SiUS181305E

2. Basic Control

2.1

Normal Operation

<Cooling Operation>
Actuator
Compressor
Outdoor fan
Four-way valve (Y1S)
Main electronic expansion valve (Y1E)
Subcooling electronic expansion valve
(Y3E)
Hot gas bypass solenoid valve (Y2S)
<Heating Operation>
Actuator
Compressor
Outdoor fan
Four-way valve (Y1S)
Main electronic expansion valve (Y1E)
Subcooling electronic expansion valve
(Y3E)
Hot gas bypass solenoid valve (Y2S)
Heating operation does not start when the outdoor temperature is above 24CDB (75.2FDB).
2.2

Compressor PI Control

The PI control of the compressor capacity is carried out to keep Te constant during cooling
operation and Tc constant during heating operation to ensure stable unit performance.
<Cooling operation>
Controls compressor capacity to adjust Te to
achieve target value (TeS).
Te setting (Set in setting mode 2)
(37.4°F)
<Heating operation>
Controls compressor capacity to adjust Tc to
achieve target value (TcS).
Tc setting (Set in setting mode 2)
(109.4°F)
Function
Operation
Compressor PI control
Cooling fan control
OFF
480 pulse
PI control
OFF
Operation
Compressor PI control
STEP 7 or 8
ON
PI control
PI control
OFF
L M (Normal)
: factory setting
3°C 6°C
(42.8°F)
L M (Normal)
: factory setting
43°C 46°C
(114.8°F) (120.2°F)
Used for high pressure protection control, low
pressure protection control, discharge pipe
temperature protection control, and compressor
operating frequency upper limit control with inverter
protection control.
This valve turns on with low pressure protection
control.
Used for high pressure protection control, low
pressure protection control, discharge pipe
temperature protection control, and compressor
operating frequency upper limit control with inverter
protection control.
This valve turns on with low pressure protection
control.
Te: Low pressure equivalent saturation temperature
TeS: Target Te value
(Varies depending on Te setting, operating
frequency, etc.)
H
9°C
(48.2°F)
Tc: High pressure equivalent saturation temperature
TcS: Target Tc value
(Varies depending on Tc setting, operating frequency,
etc.)
H
49°C
Basic Control
Remarks
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Remarks
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