Oil Return Operation - Daikin VRV EMERION REYQ-AATJA Service Manual

SiUS372201EB
7.2

Oil Return Operation

In order to prevent the compressor from running out of oil, the oil return operation is conducted to
recover oil that has flowed out from the compressor to the system side.
Tc: High pressure equivalent saturation temperature
Te: Low pressure equivalent saturation temperature
TsA: Suction pipe temperature detected by thermistor R5T
7.2.1 Oil Return Operation in Cooling Operation
Starting
 Oil return operation is not conducted before 2 hours have elapsed from the activation of power
Conditions
 After 2 hours have elapsed, oil return operation starts when the following item meets the
 Oil return control starts every 8 hours of cumulative operation of the compressor, even if the
Part name
Compressor motor
Fan motor
Electronic expansion valve (Heat exchanger right upper)
Electronic expansion valve (Heat exchanger right lower)
Electronic expansion valve (Heat exchanger left)
Electronic expansion valve (Subcooling heat exchanger)
Electronic expansion valve (Receiver gas purge)
Electronic expansion valve (Refrigerant cooling IPM)
Electronic expansion valve (Refrigerant cooling air)
Solenoid valve (Oil separator oil return)
Solenoid valve (Liquid shutoff)
Solenoid valve (Accumulator oil return)
Solenoid valve (Refrigerant adjustment)
Solenoid valve (Injection)
Four way valve (Heat exchanger right upper)
Four way valve (Heat exchanger right lower)
Four way valve (Heat exchanger left)
Four way valve (HP/LP gas pipe)
Solenoid valve (Refrigerant cooling bypass)
Ending condition
Part 4 Functions and Control
supply.
reference value.
 Total amount of oil discharged from the compressor
(The total amount of oil discharged from the compressor is computed from Tc, Te, and
compressor loads.)
reference value is not met.
Electric symbol
M1C, M2C Constant low pressure control
M1F, M2F For heat exchanger mode
Y1E Same as normal control
Y2E
Y5E
Y3E 0 pulse
Y4E 0 pulse
Y6E Same as normal control
Y7E
Y1S, Y2S ON
Y3S ON
Y4S ON
Y5S OFF
Y6S ON
Y10S Hold
Y7S
Y9S
Y8S
Y11S Same as normal control
x
A lapse of 3 minutes
&
OR
Special Control
Function of functional part
x
TsA – Te < 3qC (5.4°F)
x
A lapse of 6 minutes while the frequency is
more than that of oil return operation.
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