Edwards E-LAB 2, Instruction Manual

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© Edwards Limited 2014. All rights reserved. Page 19
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Operation
A652–07–880 Issue D
4 Operation
Note: At high inlet pressures (above 200 mbar, 2 x 10
4
Pa), the gas ballast oil return assembly will not work
correctly. If oil is to be returned to the pump when the pump is operated at continuous, high inlet
pressures, contact the supplier or Edwards for advice.
4.1 Start-up procedure
If the oil is contaminated, or if the pump temperature is below 12 °C, or if the electrical supply voltage is more than
10% below the lowest voltage specified on the voltage indicator (
Figure 7 , item 3), the pump may operate at a
reduced speed for a few minutes. If the pump continues to operate at reduced speed, the motor thermal overload
device will open and stop the pump. When the motor has cooled, the thermal overload device will reset automatically
and the pump will restart.
1. Check that the pump oil level is between the MAX and MIN marks on the bezel of the oil level sight-glass; if it is
not, refer to Section 5.4 .
2. Use the on/off switch ( Figure 1 , item 12) to switch on the electrical supply to the pump.
4.2 To achieve ultimate vacuum/pump condensable vapours
If the E-LAB 2 does not achieve the performance specified in Section 2 , make sure that this is not due to system design
before contacting the or Edwards for advice. In particular, the vapour pressure of all materials used in the vacuum
system (including pump oil, see below) must be much lower than the specified ultimate vacuum of the pump. Refer
to
Section 5.14.2 for a list of possible causes for failure to achieve the specified performance; note however that the
most common causes are:

The pressure measurement technique or gauge head is unsuitable or the gauge head is faulty.

An oil other than the recommended oil has been used and the vapour pressure of the oil is higher than the
specified ultimate vacuum of the pump.
Use the following procedure to achieve ultimate vacuum:
1. Isolate the E-LAB 2 from the vacuum system and operate the E-LAB 2 for at least 1 hour (or overnight) to
thoroughly purge the oil of contaminants.
2. Open the vacuum system isolation-valve and pump down to ultimate vacuum.
After pumping condensable vapours, if necessary, the oil can be decontaminated: use the procedure in Section 4.3 .
WARNING
Ensure that the system design does not allow the exhaust pipeline to be blocked.