Daikin VRV - WII, Service Manual

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SiUS30-604 Special Operation
Function 81
7.4 Refrigerant Drift Prevention
“Refrigerant drift prevention control” is carried out, in order to prevent refrigerant drift among
outside units during heating operation using outside multiple connection. Excessively charged
refrigerant in outside units are collected and transferred to other outside units that are running out
of gas by controlling the solenoid valve.
(1) In case of cooling/heating changeover connection
When the superheated at the evaporator outlet degree is large, open the solenoid valve (SVG) for
venting receiver gas of the outside units that are running out of gas.
(2) In case of cooling/heating simultaneous connection
When the superheated degree at the evaporator outlet is large, open the solenoid valve (SVG) for
venting receiver gas of the outside units that are running out of gas and the solenoid valve (SVL) for
pressurizing the receiver of the excessively charged outside units.
When the superheated
degree at the evaporator
outlet is large
When the superheated
degree at the evaporator
outlet is small
Normal operation
(SVG=OFF)
SVG=ON
When the superheated
degree at the evaporator
outlet is large
When the superheated
degree at the evaporator
outlet is small
Normal operation
(SVG=OFF)
(SVL=OFF)
SVG=ON
SVL=ON