Hitachi NEXT Series Instruction Manual page 66

8. STANDARD COMPONENTS AND SUBSYSTEMS [Capacity Control System]
8.4.3 Capacity Control System
Air
Intake
Air Intake Filter
1st-Stage
Blowoff Solenoid Valve (1)
2nd-Stage
1st-Stage
Blowoff Solenoid Valve (1)
Air End
2nd-Stage
Blowoff Solenoid Valve (2)
Intercooler
2nd-Stage
Air End
8.4.4 Relation between Air Consumption Rate and Capacity Control System
Air Operating
Consumption Frequency
(%) (Hz)
160VWN 160VWN
100 to 60 40 to 60
[100 to 70]
〔40 to 54〕
240VWN 240VWN
100 to 55 35 to 60
[100 to 60]
〔35 to 53〕
160VWN
60 to 5
[70 to 5]
24
240VWN
〔24〕
55 to 5
[60 to 5]
Motor
5 to 0
stopped
The DSP supports the 3 capacity control systems as above.
Depending on the varying air consumption, an appropriate system is automatically selected.
For more information, read the following page.
IMPORTANT
For changing the pressure settings, see page 27.
For changing the capacity control settings, see pages 25.
64
1st-Stage
Blowoff Solenoid Valve (2)
Aftercooler
Check Valve
Capacity Control System
①
CPCS Motor Speed Control
②
Two-Step Purge
Start/Stop Control
③
Motor Stop/Restart Control
(AUTO operation)
Flow of Purging Air and Action of Blowoff Solenoid Valve
Operation Phase
of DSP
Starting
Loading
Purging
Stopping
Power Interruption
Blowoff
Silencer
Pressure
Sensor
PS2
Air
Discharge
※ Figure in 〔
Pressure Settings (MPa)
Setting
Factory
Items
0.75
Standard
〔0.93〕
0.77
Upper
(purge start)
〔0.95〕
0.72
Lower
(purge stop)
〔0.90〕
0.72
Lower
(motor restart)
〔0.90〕
Action of Blowoff Solenoid Valve
(1) (2)
Opened fully Closed fully
Closed fully Closed fully
Opened fully Closed fully
Opened fully Closed fully
Closed fully Opened fully
〕 are for 0.93MPa models.
SW3
Lower
Settings
Example
AUTO ON
（INVA）
0.65
or
〔0.83〕
AUTO OFF
（INVB）
0.75
AUTO ON
〔0.93〕
（INVA）
or
AUTO OFF
0.65
（INVB）
〔0.83〕
0.65 AUTO ON
〔0.83〕 （INVA）