Accessories
11
Continous operation
With "pumping station on", the electronic drive unit sends a signal to the configured ac-
cessory connection to switch on the backing pump. This signal can also be used for con-
trolling a fore-vacuum safety valve.
Intermittend opera-
tion (diaphragm
pumps only)
Intermittend operation can extend the life expectancy of the membrane of a connected
diaphragm pump. Either a diaphragm pump with built-in semiconductor relay or an inter-
connected relay box with semiconductor relay is required for intermittend operation. The
backing pump is switched on and off in dependence of the turbopump's power consump-
tion. A relation to the supplied fore-vacuum pressure is derived from the power consump-
tion. The switching off and switching on thresholds for the backing pump are adjustable.
Fluctuations in the power consumption of idling turbopumps and type-dependent varying
fore-vacuum pressures of the backing pumps require the switching thresholds to be set
separately for the intermittend mode.
Pfeiffer Vacuum recommends the intermittend mode between 5 and 10 hPa. A pressure
gauge and a dosing valve are required to set the switching thresholds.
Switch on the vacuum system via the function "pumping station" and await the run-up.
Generate a fore-vacuum pressure of 10 hPa by gas inlet via dosing valve.
Read and note the parameter
[P:316]
.
Adjust the switch on threshold backing pump via parameter
[P:711]
to the determined
drive power for a fore-vacuum pressure of 10 hPa.
Reduce the fore-vacuum pressure to 5 hPa.
Read and note the parameter
[P:316]
.
Adjust the switch off threshold backing pump via parameter
[P:710]
to the determined
drive power for a fore-vacuum pressure of 5 hPa.
Delayed switching on
Switching on the turbopump and the backing pump at the same time can result in un-
wanted gas flows. Depending on process or application requirements, the backing pump
can be switched on with a delay. The switch-on delay depends on the rotation speed of
the turbopump and is fixed in the electronic drive unit at 6 Hz.
The switch-on delay signal can also be used for switching a fore-vacuum safety valve.
7
Accessories
An overview about original Pfeiffer Vacuum accessories for the designated device can
be found in the operating instructions of the respective vacuum pump.
8
Technical data
Parameter
Relay box, shielded,
for backing pumps
Relay box, shielded,
for backing pumps
Mains requirement: frequency (range)
50/60 Hz
50/60 Hz
Mains requirement: voltage (range)
100-240 (± 10 %) V AC
100-240 (± 10 %) V AC
Contact rating
7 A
20 A
Control voltage
24 V DC
24 V DC
