6 Operation
6.1 Putting the vacuum pump into operation
Before switching on
1. Check the lubricant levels on both sight glasses.
2. Compare the specifications on the motor rating plate with the available mains voltage and fre-
quency.
3. Make sure that the suction chamber is free from all foreign matters.
4. Check the vacuum pump for visible damage and put the vacuum pump into operation only in a
correct state.
5. Protect the vacuum pump from sucking in contamination using suitable measures (e.g. dust filter).
6. Make sure that the shut-off units on the pressure side open before starting the pump.
6.2 Switching on the vacuum pump
WARNING
Danger of poisoning due to toxic process media escaping from the exhaust pipe
During operation with no exhaust line, the vacuum pump allows exhaust gases and vapors to escape
freely into the air. There is a risk of injury and fatality due to poisoning in processes with toxic process
media.
► Observe the pertinent regulations for handling toxic process media.
► Safely purge toxic process media via an exhaust line.
► Use appropriate filter equipment to separate toxic process media.
CAUTION
Danger of burns on hot surfaces
Depending on the operating and ambient conditions, the surface temperature of the vacuum pump
can increase to above 70 °C.
► Provide suitable touch protection.
Supplementary Information for Roots pumps with special overflow valves
Upon request, you can obtain supplementary information
PW0022
.
Procedure for open, non-blocked overflow valves
1. The customer must provide an appropriate start-up circuit (e.g., contactor circuit) for switching on
the roots pump simultaneously with, or after, the backing pump.
2. Allow the vacuum pump to warm up with the vacuum flange closed, for approx. 30 minutes prior to
the process start.
The overflow valve is open at the beginning of evacuation in high pressures ranges. This protects the
Roots pump from overload. The overflow valve closes as soon as the differential pressure between the
suction side and pressure side reaches or exceeds
75 hPa
:
Procedure in case of a blocked overflow valve
1. Switch on the Roots pump only at a pressure at which the backing pump can take over the deliv-
ered gas quantity.
2. Limit the torque in the event of overload with a frequency converter, if you wish to switch on the
roots pump simultaneously with the backing pump.
3. Allow the vacuum pump to warm up with the vacuum flange closed, for approx. 30 minutes prior to
the process start.
4. Switch off the roots pump immediately after the backing pump has been switched off or has failed.
Operation
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