LEYBOLD VARODRY CD200, Operating Instructions Manual

Page: 20 / 52

6 Operation
Start the pump by applying the supply voltage. The pump can be started up
to 20 times per hour.
WARNING:
Connect the pump to an exhaust gas pipework if other gases than clean air are
pumped.The exhaust of the pump must not be blocked or constricted. Never operate
the pump with the seal-off stoppers in place blanking off the exhaust port.
6.1 Switching off
Switch off the pump by disconnecting from the mains voltage.
If condensable vapours have been conveyed, operate the pump for 30
minutes with closed process valve and open gas-ballast before switching off
in order to evaporate the residual condensate.
The pump will run down for several seconds. Due to the design, the vacuum
system is then vented through the pump, if no valve is closed between the
pump and the vacuum system. In this case, the pump runs backwards until
the pressure is equalised. In case of vacuum chambers exceeding a defined
volume a valve must be closed before switching off the pump to avoid over-
speeding of the pump and contamination of the vacuum system with dust
streaming back from the exhaust pipework.
The maximum chamber sizes to be vented through the pump are:
VARODRY VD 65: 500 l
VARODRY VD 100: 800 l
VARODRY VD 160-200: 1000 l
The ventilation process may take several minutes, depending on the size of
the container. Wait for the pressure equalisation before opening the vacuum
system or disconnecting the pump from the vacuum system.
In order to avoid back-venting of the vacuum chamber close the inlet of the
pump with a valve before switching off. A suitable inlet non return valve is
available as optional accessory.
300766038_002_C3 - 09/2021 - © Leybold
20
Operation