4-Way Valve Control - Daikin Sky Air R-407C Service Manual

ESIE02–01
3.6

4-way Valve Control

Applicable units RYP71-250B
Purpose The purpose of the 4-way valve control is to control how the superheated refrigerant passes through
the 4-way valve. The 4-way valve control carries out the changeover switching of the 4-way valve. This
changeover switching is only carried out during operation, because pressure difference is required to
move the internal cylinder.
When...
Cooling
Heating
Method The table below describes the 4-way valve control operation.
In...
Heating, except for defrosting
Time chart The time chart below illustrates the 4-way valve control.
Compressor
Unit mode
Defrosting
4-way valve
Used input The 4-way valve control uses the following inputs:
Input
Indoor air temperature R1T (auto changeover)
Outdoor heat exchanger temperature R2T (defrost)
Part 2 – Functional Description
Then the 4-way valve connects the outlet of the compressor with...
Outdoor heat exchanger.
Indoor heat exchanger.
Cooling
Dry keep
Defrosting
ON
OFF
Cooling / dry keep
Heating
ON
OFF
ON
OFF
Overview of the heating mode functions
The 4-way valve is...
ON
OFF
Connection on
indoor PCB
X19A
—
1
2
3
4
5
Connection on
outdoor PCB
—
X5A
2–45