28100031
100 08/2017
Page: 4
Watch for damages to the protective grid and repair
if necessary.
Soiled suction filters reduce the pumping capacity.
Clean fan hood, fan grid, oil cooler, cooling
fins and surfaces of the unit to avoid
overheating.
Oil and oil separation
Check the oil level regularly: During operation, the
oil level may not drop below 2/3 of the view window
MI (Fig. 2).
2. Control instructions
VARIAIR DIRECT SCREW 1500
2.1
Operating modes of the rotary screw unit
With SPS control:
• SPS requirements (terminal strip X6 3/4):
24 V SPS release signal
• feedback for SPS (terminal strip X6 1/2):
via relay output 04 on the control board of the FU
• Operation at fixed speed of rotation possible and adjustable in parameter 19-29 while the unit is running
• SPS operational mode with set rotation speed (terminal strip X6 6/7):
0-10 V signal of the set speed of rotation
Vacuum revolutions 110 (min.) - 200 Hz (max.)
Pressure revolutions 80 (min.) - 165 Hz (max.)
Without SPS control:
• Vacuum and pressure kept at a constant level by internal PI regulator.
Parameter 19-38 to 1
Nominal value can be set in parameter 19-37
Setting range: Vacuum 200-1000 mbar abs
Pressure 1000-2000 mbar abs
The parameters 19-32 to 19-34 have to be set according to the control mode.
• Operation with fixed speed or rotation adjustable and changeable in parameter 19-29 while the unit is
running.
• Signal of the nominal speed 0-10 V by the connection of an external potentiometer at terminal strip X6
6/7 on e-plate.
Vacuum revolutions 110 (min.) - 200 Hz (max.)
Pressure revolutions 80 (min.) - 165 Hz (max.)
• Master-slave mode of operation required speed of rotation of the master screw will be passed on to the
slave (at present not yet available)
Change of oil and oil filters
- change oil and oil filters after 5000 operating
hours
- at least once per year
Drain the waste oil by opening the ball valve
of the oil pump (figure 2).
