8.4 Operating modes
The following operating modes are possible:
● Operation without control unit
● Operation via an external control unit
● Operation via RS-485 and Pfeiffer Vacuum display and control unit or PC
The connection of a Pfeiffer Vacuum display and control panel permits the controlling of the vacuum
pump via the parameters fixed in the electronic drive unit.
Automatic start
After bypassing the contacts at pins 2, 7, 5 on the connecting plug or when using a con-
necting cable with respective bridges and applying the supply voltage, the vacuum pump
starts up immediately.
Pfeiffer Vacuum therefore recommends switching on the voltage supply immediately before
operation.
Operate without control unit
1. Connect the respective connecting cable with bridges to the power supply plug of the electronic
drive unit.
2. Provide the current supply for the power supply pack.
3. Switch on the power supply pack with switch S1.
After applying the operating voltage, the vacuum pump carries out a self-test to check the supply volt-
age. After a successfully completed self-test, the vacuum pump starts.
Operate via the external control
► Connect the remote control via the 15-pin D-Sub socket.
The control is carried out by means of "PLC level".
Operate with peripheral devices DCU or HPU.
1. When handling the Pfeiffer Vacuum display and control unit, observe the associated operating in-
structions:
– "DCU" operating instructions available from the
– "HPU" operating instructions available from the
2. Connect the respective peripheral device to the 15-pin D-Sub socket.
3. Switch on the power supply pack with switch S1 or on the peripheral device.
4. Make the desired settings via the RS-485 using the peripheral device.
8.4.1 Normal operation
The vacuum pump starts in boost mode for max. 5 minutes with the maximum speed. The current is
monitored at the same time. If the current is below a threshold value, the speed is controlled down to
nominal rotation speed. In case the power input increases again, automatic increase of the speed does
not take place. An increase in speed is reached again after vacuum pump stop / start.
Setting the related parameters
1. Set the parameter
[P:002]
to "0".
2. Set the parameter
[P:026]
to "0".
3. Check the set rotation speed (parameter
[P:309]
or
[P:398]
).
8.4.2 Stand-by operation
Pfeiffer Vacuum recommends stand-by operation for the vacuum pump during breaks in processes or
production.
● The factory setting is 66.7 % of the nominal speed.
● Stand-by operation has priority over rotation speed setting mode.
● With active stand-by mode, the electronic drive unit reduces the speed of the vacuum pump in the
range of
30 to 100%
of the nominal speed.
Activate stand-by rotation speed
1. Set the parameter
[P:717]
to the required value in %.
2. Set the parameter
[P:026]
to "0".
Operation
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