28
The Pfeiffer Vacuum parameter set
Adjust the parameter
[P:777]
according to the pump type.
Once the nominal rotation speed is attained, the pump will run idle unless additional gas
loads are entered. Depending on process or application requirements, the nominal rota-
tion speed can be reduced in rotation speed setting mode or standby mode.
7.4.10 Operation mode backing pump
Operation of a connected backing pump via the electronic drive unit depends on the
backing pump type.
Adjust the parameter
[P:025]
to the desired value.
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 operation (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 signal can also be used for switching a fore-vacuum safety valve.
300
1000 Hz
HiPace
Nominal rotation speed confirmation [P:777]
Operating mode [P:025]
Recommended backing pump
"0" Continuous operation
All backing pumps
"1" Intermittent operation
Diaphragm pumps only
"2" Delayed switching on
All backing pumps
"3" Delayed intermittent operation
Diaphragm pumps only
