The Pfeiffer Vacuum parameter set
31
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.
9.4.11 Operation with accessories
Depending on the configuration, various accessories can be connected to the turbopump
and controlled via parameter of the electronic drive unit.
Heating
Switch on or off the heating via parameter
[P:001]
.
The activation of a connected casing heating depends on rotation speed switchpoint 1
(factory setting: 80 % x f
Nominal
).
Sealing gas valve
Switch on or off a sealing gas valve which is connected to a pre-configured output via
parameter
[P:050]
.
9.4.12 Vent modes
The turbopump can be vented only after the function "pumping station" has been
switched off. Signals are sent to configured outputs with a fixed delay of 6 s. There are
three options for operation with a venting valve connected.
Enable venting via parameter
[P:012]
.
Select the venting mode via parameter
[P:030]
.
Delayed venting
Start and venting time after "pumping station off" are configurable and depend on the ro-
tation speed of the turbopump.
Parameter
[P:030]
= 0
Adjust the venting rotation speed in % of the nominal rotation speed via parameter
[P:720]
.
Adjust the venting time in s via parameter
[P:721]
.
If the venting rotation speed is underrun, the venting valve will open for the set venting
time. In the event of a power failure, venting will occur if the set venting rotation speed is
underrun. In this case, the venting period depends on the residual energy delivered by
the moving rotor. When power is restored, the venting process is interrupted.
