Capacity Control System V-Type; Purging Air Flow And Action Of Blowoff Solenoid Valve; Relationship Between Air Consumption Rate And Capacity Control System - Hitachi NEXT Series Instruction Manual

8. STANDARD COMPONENTS AND SUBSYSTEMS [Capacity Control System]

8.4.4 Capacity Control System V-type

Air
intake
Air intake filter
1st-stage
Blowoff solenoid valve (1)
2nd-stage
1st-stage
Blowoff solenoid valve (1)
airend
2nd-stage
Blowoff solenoid valve (2)
Intercooler
2nd-stage
airend

8.4.5 Relationship between Air Consumption Rate and Capacity Control System

Air Operating frequency (Hz)
consumption
90kW
(%)
60 to 35
100 to 45
〔52 to 35〕
45 to 5 25
5 to 0 Motor stopped
The air compressor supports the three (3) capacity control systems as shown above.
Depending on the varying air consumption, an appropriate system is automatically selected. For more information, see
the following page. Operation frequency is shown by Digital monitor. LCD monitor displays up to first figure after
decimal place.
IMPORTANT
To change the pressure setting and the capacity control
type, 2.4 2 and 3.4.3.
.
70
1st-stage
Blowoff solenoid valve (2)
Aftercooler
Check valve
Capacity control system
110kW
60 to 37
①
〔51 to 37〕
CPCS Motor speed control
②
Two-step purge control
③
Motor stop/restart control

Purging Air Flow and Action of Blowoff Solenoid Valve

Operation phase
Starting
Loading
Purging
Stop
Power Interruption
Blowoff
silencer
Pressure
sensor
PS2
Air
discharge
※ Figure in[
Pressure settings psi [MPa]
Setting items Factory
Control
125 [0.86]
pressure
Cut-out
128 [0.88]
pressure
Cut-in
123 [0.85]
pressure
Cut-in
123 [0.85]
pressure
Blowoff solenoid Blowoff solenoid
valve (1) valve (2)
Fully opened Fully closed
Fully closed Fully closed
Fully opened Fully closed
Fully opened Fully opened
Fully closed Fully opened
]are for 125 psi(0.86 MPa) models.
SW3
Lower
settings
example
AUTO ON
（VSDA）
100 [0.69] or
AUTO OFF
（VSDB）
AUTO ON
104 [0.72]
（VSDA）
or
AUTO OFF
85 [0.59]
（VSDB）
AUTO ON
85 [0.59]
（VSDA）