Basic Control; Normal Operation - Daikin FCQ18PVJU Service Manual

Basic Control

2. Basic Control
2.1

Normal Operation

 Cooling Operation
Actuator
Compressor
Outdoor unit fan
Four-way valve
Main electronic expansion valve (EV1)
Subcooling electronic expansion valve
(EV2)
Hot gas bypass valve (SVP)
Receiver gas discharging valve (SVG)
 Heating Operation
Actuator
Compressor
Outdoor unit fan
Four-way valve
Main electronic expansion valve (EV1)
Subcooling electronic expansion valve
(EV2)
Hot gas bypass valve (SVP)
Receiver gas discharging valve (SVG)
∗ Heating operation is not functional at an outdoor air temperature of 86°FDB or more.
17
Operation
Compressor PI control
Cooling fan control
OFF
1400 pls
PI control
OFF
OFF
Operation
Compressor PI control
STEP8
ON
PI control
0 pls
OFF
OFF
Remarks
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.
—
Remarks
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.
The fan step changes to STEP1 with high pressure
> 454 psi.
⎯
⎯
⎯
This valve turns on with low pressure protection
control.
—
SiUS28-902_a
Function