32
6. SYSTEM OF EACH COMPONENT [Capacity Control System]
6.2.6 Alternative Cutoff/Cutin
Pressure Function
Alternative cutoff/cutin pressure function is an op-
tional feature of the S- and M-type
A
un-
der the I-type capacity control. Alternative cutoff
and cutin pressures are lower than the standard
ones. You may use this function, when a com-
pressed air demand is less (i.e. during overtime),
and thus save the power as indicated by the shaded
areas in the illustration.
If you want to use this function, contact your
Hitachi distributor to modify the control circuit,
install an external on/off switch, and set the cutoff
and cutin pressures to as required.
To activate this function, turn on the external on/
off switch. Make sure that the
LOAD
light becomes
on (flashing) and off when the
A
is respec-
tively loading and unloading. (Note that this ac-
tion of the
LOAD
light is different from when the
standard cutoff and cutin pressures are used.) To
deactivate this function (or to return to the stan-
dard cutoff and cutin pressures), turn off the ex-
ternal on/off switch.
・
The ECOMODE function does not work when the al-
ternative cutoff/cutin pressure function is activated.
・
The alternative cutoff/cutin pressure function does not
work when the compressed air demand causes the
U-type (not the
I
-type) to be selected.
IMPORTANT
automatically used with the
ECOMODE
light
flashing. The cutoff pressure shifts from stan-
dard to optional step-by-step until it reaches
the cutin pr 0.05 MPa or a load-un-
load cycle decreases to below 30 seconds. Thus
you can save the power as indicated by the
shaded areas in the illustration.
(2) Precautions
・
When you use the ECOMODE function, in-
stall an air receiver tank that has a larger
capacity than otherwise required. For more
information, see page 36.
・
Do not change the reference time of 30 sec-
onds although it is accessible on the fourth
of the capacity control setting screens.
・
This function cannot work when (1) the
A
is operating under the P- or U-
type capacity control and (2) you have
changed the preset standard cutoff pressure.
Power Saving Effects
Loading Unloading
Time
Cutoff
Pressure
Cutin
Pressure
Pressure
Automatic Shifting of
Cutoff Pressure from
Standard to Optional
Preset Cutoff/Cutin Differential:
0.1 MPa
Optional Cutoff Pressure:
Cutin Pr 0.05 MPa
Cutoff pressure automatically shifts from standard to optional
until a cycle time decreases to 30 seconds or below.
;
;
;;
;;
ON (flashing)
ON (non-flashing)
LOAD Light
when loading
ON
OFF
External ON/OFF Switch
Time
Power Saving Effects
Loading Unloading
Standard Cutoff
Pressure
Standard Cutin
Pressure
Alternative
Cutoff
Pressure
Alternative
Cutin
Pressure
Pressure
