•
The supply of compressed air to the load net-
work begins.
•
The unit is in on-load operation.
Shutting the unit down
•
After pressing of the OFF key on the control
panel of the DELCOS XL compressor control,
the solenoid valve (-24-(Y1)) is switched to a
zero-current state.
•
The upper control space of the adjusting cylin-
der (2.1) is ventilated by the solenoid valve
(-24-(Y1)). The pressure spring in the adjusting
cylinder causes the butterfly valve (-2.2-) in the
intake regulator to close.
•
After 30 seconds, the drive motor (-3-) and the
cooling air fan (-19-) are shut down.
The cooling water solenoid valve (-32-(Y6)) is
shut in a zero-current state (only L xxx W).
Automatic operation (OPEN-CLOSED opera-
tion)
•
If the pressure at the line pressure sensor (-13-
(B1)) reaches the set upper switching point, the
solenoid valve (-24-(Y1)) is switched to a zero-
current state.
•
The upper control space of the adjusting cylin-
der (2.1) is ventilated by the solenoid valve
(-24-(Y1)). The pressure spring in the adjusting
cylinder causes the butterfly valve (-2.2-) in the
intake regulator to close.
•
The pressure vessel is depressurised through
the blow-off valve (-25-) to off-load operation
pressure (residual pressure).
•
The screw compressor now runs in off-load op-
eration.
•
The cooling water solenoid valve (-32-(Y6)) is
opened and closed based on the discharge
temperature (only L xxx W – water-cooled
units).
•
If the pressure at the line pressure sensor (-13-
(B1)) does not drop to the set lower switch-
ing point within the set run-on time (e.g. 120
seconds), the drive motor (-3-) and the cooling
air fan (-19-) are shut down and the unit is de-
pressurised to atmospheric pressure. The cool-
ing water solenoid valve (-32-(Y6)) is shut in a
zero-current state (only L xxx W)
•
The unit is now in stand-by mode and can
restart at any time once the line pressure drops
to the set lower switching point (see section “S-
tarting the unit”).
•
If the line pressure drops to the pre-set lower
switching point within the set motor run-on
time, the solenoid valve (-24-(Y1)) is supplied
with current again and the blow-off valve (-25-
(Y4)) is shut.
•
The unit goes back to on-load operation.
3.7
Lubricant system
The screw compressor unit’s drive motor is fitted
with an automatic motor lubrication system.
Function of the motor lubrication system
The automatic motor lubrication system guaran-
tees permanent lubrication of the motor bearings.
The installed lubricators are powered (24 VDC)
via the compressor control when the drive motor is
running. The grease quantity set at the lubricator
is distributed during several cycles depending on
the motor service life measured.
An empty grease cartridge or a fault on the lubri-
cator is indicated on the compressor control by
means of a message [Warning: mot.lubr. sys] (also
refer to the operating instructions for the compres-
sor control DELCOS XL).
Structure of the lubricators
(2x per drive motor)
1
2
3
4
[1]
Socket for connection cable
[2]
Lubricator drive
[3]
Grease cartridge (not refillable)
[4]
Support bracket
