System Control L15 Rs-L22 Rs - Gardner Denver L15 Original Operating Manual

5. Design and functioning
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-energized.
The suction regulator (- 2 - Fig. 4) is vented and
•
closed.
The pressure reservoir (- 5 - Fig. 4) is depressurized
•
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
energized again.
The unit now changes over to on-load operation.
•
Stopping the system
After pressing the OFF button
•
operating panel, the solenoid valve (- Y1 - Fig. 4) is
de-energized.
The suction 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.

(Fig. 15) on the


5.5.2 System control L15 RS-L22 RS

Standstill of the system
When the system is at rest the suction regulator
•
(- 2 - Fig. 4) is closed.
The solenoid valve (- Y1 - Fig. 4) is de-energized.
•
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. 58 to 65 PSI
•
is maintained in the pressure tank (- 5 - Fig. 4), as
the minimum pressure and 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. 65 PSI.
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, 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 58 to 65 PSI.
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 de-energized (closed) and the
remaining pressure in the reservoir is discharged via
the orifice (- 9 - Fig. 4).
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