Gardner Denver L07, Оригинальное руководство по эксплуатации и обслуживанию, Страница: 23 / 60

4. Design and functioning
21
Automatic operation (open-close operation)

When the pressure reaches the upper switching
point set on the network pressure sensor (-7 - Fig. 4),
solenoid valve (Y1 Fig. 4) is de-energised.

The intake regulator (- 2 - Fig. 4) is vented and
closed.

The pressure reservoir (- 5 - Fig. 4) is depressurised
via the intake filter.

The compressor is now running in idle mode.

If the mains pressure does not fall within 90 seconds
(adjustable) to the lower switching point, the system
shuts down.

If the lower switching point is reached in less than
90 seconds, the solenoid valve (- Y1 - Fig. 4) is
energised again.

The unit now changes over to on-load operation.
Stopping the system

After pressing the OFF button

 (Fig. 16) on the
operating panel, the solenoid valve (- Y1 - Fig. 4) is
de-energised.

The intake regulator (- 2 - Fig. 4) closes and the
tank (- 5 - Fig. 4) is relieved.

After 30 seconds, the drive motor (- 3 - Fig. 4) is
shut down.
4.5.2 System control L07RS-L11RS
(See also operating instructions for the compressor
control GD PILOT LRS)
Standstill of the system

When the system is at rest the intake regulator
(- 2 - Fig. 4) is closed.

The solenoid valve (Y1 Fig. 4) is de-energised.

The pressure reservoir (- 5 - Fig. 4) is bled via the
blow-off line (- 2.2 - Fig. 4) and the orifice (-9 - Fig. 4)
into the suction channel.
Starting the system

The motor (- 3 - Fig. 4) starts up.

The compressor extracts a certain volume of air via
a start valve (- 2.1 - Fig. 4). Pressure builds up in
the reservoir and closes the regulator.

This way, constant pressure of approx. 4 to 4.5 bar
is maintained in the pressure tank (- 5 - Fig. 4), as
the pressure holding non-return valve (- 8 - Fig. 4)
still remains closed at this pressure level.

Oil is supplied to the screw compressor (- 3 - Fig. 4)
due to the pressure differential between the
pressure reservoir (- 5 - Fig. 4) and the place of
injection in the screw compressor (- 4 -).

If pressure in the load system falls below the
minimum pressure programmed on the control
system, the solenoid valve (-Y1- Fig. 4) is energized
and opened. Pressure then continues to build up in
the pressure reservoir (- 5 - Fig. 4).

The minimum pressure valve (- 8 - Fig. 4) opens
when the pressure reservoir is approx. 4.5 bar.

Compressed air is now delivered into the consumer
network.
Stopping the system

After pressing the OFF button on the control panel
of the compressor control system GD PILOT LRS,
the magnet valve (- Y1 - Fig. 4) is de-energized
(closed) while the drive motor is still running.

The pressure reservoir (- 5 - Fig. 4) is depressurized
to a constant pressure of 4 to 4.5 bar.

The drive motor (- 3 - Fig. 4) reduces its number of
revs to the set minimum value and comes to a
standstill after 30 seconds have passed.

Once the drive motor has stopped, solenoid valve
(- Y1 - Fig. 4) is deenergized (closed) and the
remaining pressure in the reservoir is discharged via
the orifice (- 9 - Fig. 4).