Gardner Denver L Series Original User And Service Manual page 24

Stopping the system

Solenoid valve (-23-(Y1)) is de-energized when the
STOP button on the operating panel of the
compressor controller TS is pressed.

The upper control space of the adjusting cylinder
(2.1) is ventilated by the solenoid valve (-23-(Y1)),
the pressure spring in the adjusting cylinder causes
the choke valve (-2.2-) in the intake regulator to
close.

After 30 seconds, the drive motor (- 3 -) and the
cooling air ventilator motor (- 18 -) are shut down.
The cooling water solenoid valve -28- de-energized
and closes (only water-cooled units).
Automatic operation (open-close operation)

When the pressure reaches the unload set point
at the network pressure sensor (-13 - (B1)),
solenoid valve (- 23 - (Y1)) is de-energized.

The upper control space of the adjusting cylinder
(2.1) is ventilated by the solenoid valve (-23-(Y1)),
the pressure spring in the adjusting cylinder causes
the choke valve (-2.2-) in the intake regulator to
close.

The oil separator tank is relieved to blow down
pressure (residual pressure) via the blow-off valve
(- 24 -).

The screw compressor is now running in the offload
mode.

The cooling air ventilator (- 18 -) is switched on or
off in dependence upon the final compression
temperature (only air-cooled units).

The cooling water solenoid valve (-33-(Y6)) is
opened and closed depending on the compression
end temperature (only water-cooled units).

When the pressure at the network pressure sensor
(- 13 - (B1)) does not fall to the load set point
within the set motor run-on time (e.g. 120
seconds), the drive motor (- 3 -) and the cooling air
ventilator motor (- 18 -) are shut down and the
system is depressurized to atmospheric pressure.
The cooling water solenoid valve -28- de-energizes
and closes (only water-cooled units).

The system is now in the "stand-by" mode and can
restart at any time when the network pressure falls
to the load set point (see section "Starting of the
system").

When the pressure falls to the load set point before
the set motor run-on time has elapsed, solenoid
valve (- 23 - (Y1)) is energized again.

The unit now changes over to on-load operation
WARNING
Do not stop the Unit using the Emergency Stop Button unless
there is a danger to the product or of personnel injury.
Using the Emergency Stop Button, disconnect, or breaker to
stop the Unit will not all the Unit to go through an unloading
sequence, and could result in damage to the Motor, Stater, or
other electrical components. Damage caused in this manner
is not covered by the manufacturer's Warranty.
13-25-639 v00 Page 23