Hitachi NEXT Series Instruction Manual page 65

8.4.2 Typical Change of Pressure
⑴ Standard Offline-or-Online, 0%-or-100%-Capacity, 2-Step Control
Starting and
Pressure
Raising
110
94
Air Receiver Pressure
psi
6
⑵ Optional AUTO Operation
（2） Stop Delay
（1） Stop Delay
(15 minutes)
Starting
and
Loading
Pressure
Raising
110
94
psi
6
⑶ SAVE Mode Operation
Starting
and
Loading Unloading
Pressure
Raising
110
＊ 97 （ minimum）
94
Air Receiver
Pressure
psi
6
IMPORTANT
If the fixed speed machine is continuously loaded for a long period of time, condensate drain in blowoff air pipe may blowout from
blowoff silencer when unload start. To prevent blowout, air compressor unloads 0.5 second every 30 min when loading continue.
8. STANDARD COMPONENTS AND SUBSYSTEMS [Capacity Control System]
Loading Unloading
Time
（3） Start Delay
(30% load)
(10 seconds)
Repeated Automatic
Loading/Unloading
Motor Stop
Air Receiver Pressure Indications on LCD
Time
Power Save Operation
load/unload cycling interval
（standard 30 seconds）
Loading Unloading
Loading Unl o adi n g
Time
Loading
Air End Outlet Pressure
⑴ Stop Delay Time – 10 minutes are required to
keep the motor operating long enough to cool
down sufficiently.
Automatic
Motor Restart
If the third stop extends over 120 minutes,
however, the motor must keep operating for
more than 30 minutes after restarting.
⑵ Stop Delay Time – The DSP is continually cal-
culating a load ratio. If the load ratio is 30%
and the motor has stopped/restarted maximum
3 times for the past 150 minutes, then the
motor stops.
Air End
Outlet Pressure
⑶ Stop Delay Time – 10 seconds are required to
complete blowing off the compressed air and
to be prepared to restart.
NOTE:
Loading Unl o adi n g
This is an example of power save operation,
based on the target pressure of：0.67 MPa (97
psi) and the load/unload cycling interval of 30
seconds. The target pressure with an asterisk
may vary depending on the air receiver's capacity
and the air consumption.
Air End
Outlet
Pressure
63