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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).
Summary of Contents for L07
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