Figure 25 - Continuously Variable Capacity Control For Fr3100 Compressor - Daikin EWYD-BZ Series Installation, Maintenance & Operation Manual

1
a
Spring Force + Discharge Pressure  Cylinder Pressure = Slide Valve Moves Towards Unload
1
b
Cylinder Pressure  Discharge Pressure + Spring Force = Slide Valve Moves Towards Load
Load compressor
High pressure oil is admitted to the capacity control cylinder. Oil
pressure overcomes the force of the spring supplemented by
discharge pressure acting on the unload side of the piston, moving
the slide valve towards the maximum load position.
Unload compressor
Oil is vented from the capacity control cylinder. The force of the
spring supplemented by discharge pressure acting on the unload
side of the piston moves the slide valve towards the minimum load
position.
Hold slide valve position
The slide valve is hydraulically locked at the desired load position.

Figure 25 - Continuously variable capacity control for Fr3100 compressor

a Compressor unloading
1 Oil supply
2 De-energised (closed)
3 Energised (open)
4 Oil vent
5 Unload
6 Spring expands
7 Discharge pressure acts on this side of piston
b Compressor loading
1 Oil supply
2 Energised (open)
3 De-energised (closed)
4 Oil vent
5 Load
6 Spring compressed
7 Discharge pressure acts on this side of piston
D-EIMHP00508-16EN - 42/64
B
2
B
2
C C A
APACITY ONTROL CTION
A
4
3
A
4
3
S
OLENOID
De-energise (close)
Energise (open)
De-energise (close)
6
5
7
6
5
7
1
V A S V
ALVE OLENOID
Energise (open)
De-energise (close)
De-energise (close)
B
ALVE