Special Control; Pump Down Residual Operation - Daikin VRV EMERION RXYQ-AATJA Service Manual

Special Control

7. Special Control

7.1

Pump Down Residual Operation

If the liquid refrigerant stays in the evaporator at the startup of a compressor, this liquid refrigerant
enters the compressor, thus resulting in diluted oil in the compressor and then degraded lubrication
performance.
Consequently, in order to recover the refrigerant in the evaporator while the compressor stops, the
pump down residual operation is conducted.
Pc: High pressure sensor detection value
Pe: Low pressure sensor detection value
Ta: Outdoor air temperature
Te: Low pressure equivalent saturation temperature
DSH: Discharge pipe superheating degree
Part name
Compressor motor
Fan motor
Electronic expansion valve (Heat exchanger main)
Electronic expansion valve (Heat exchanger left)
Electronic expansion valve (Refrigerant cooling IPM)
Electronic expansion valve (Subcooling heat exchanger)
Electronic expansion valve (Refrigerant auto charge)
Electronic expansion valve (Refrigerant cooling air)
Solenoid valve (Oil separator oil return)
Solenoid valve (Hot gas bypass)
Solenoid valve (Accumulator oil return)
Solenoid valve (Four way valve)
Solenoid valve (Injection)
Ending condition
115
Electric
symbol
RXYQ72AA: 37.5 rps, —
RXYQ96/120AA: 60.0 rps, 60.0 rps
M1C, M2C
RXYQ144/168AA: 60.0 rps, 37.5 rps
RXYQ192-240AA: 37.5 rps, 37.5 rps
M1F, M2F For heat exchanger mode
Y1E Same as normal control
Y6E
Y2E Same as normal control
Y3E 0 pulse
Y4E 40 pulse
Y5E Same as normal control
Y1S, Y2S ON
Y3S OFF
Y4S OFF
Y5S Hold
Y6S ON
A lapse of 6 minutes
SiUS342303E
Function of functional part
Part 4 Functions and Control