Si30-408 Method of Troubleshooting
Troubleshooting 85
3.4 Structure and Movements of Four-way Valve
Four way valve is a representative
valve which is used for heat pump type
air conditioner. This valve functions to
selection flow direction of superheated
refrigerant discharged from
compressor. In heating operation, the
valve feeds the refrigerant to indoor
heat exchanger. While in cooling and
defrosting in heating, the valve feeds to
outdoor heat exchanger.
For VRV system standard unit, one
four-way valve is installed, however, for
some units of other series, plural valves
may be installed.
Moreover, there is two-way valve or
three way valve operated with the same
mechanism.
Movement in Cooling
From discharge of compressor
From indoor unit
heat exchanger
To suction of
compressor
To outdoor
heat exchanger
Coil: not energize
Internal plunger moves
Internal piston moves according to
pressure difference between high
pressure and low pressure