Start-Up; To Achieve Ultimate Vacuum - Edwards E2M28 Instruction Manual

4.3

Start-up

Do not block the pump outlet or allow the outlet pressure to rise above 1.5 bar absolute as the oil
box may fracture and may cause injury to people nearby.
If the oil is contaminated, or if the pump temperature is below 13°C, or if the electrical supply voltage is more than
10% below the lowest voltage specified for the pump, the pump may operate at a reduced speed for a few minutes.
On single-phase pumps, 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 5.3.
2. Turn the gas-ballast control to the required position (refer to
3. Switch on the electrical supply to the pump.
4. Check that the oil-level in the sight-glass drops slightly (by 3 to 5 mm) after start-up. This shows that the pump
has primed with oil.
5. If the pump fails to prime, operate the pump with the inlet open to atmosphere for approximately 30 seconds,
then isolate the inlet and check that the oil-level drops by 3 to 5 mm.
6. To achieve ultimate vacuum, pump condensable vapours or decontaminate the pump oil, refer to the procedures
in Section 4.4, 4.5 and
4.4

To achieve ultimate vacuum

If the pump does not achieve the performance specified in
design before contacting the supplier or Edwards for advice, In particular, the vapour pressure of all materials used
in the vacuum system (including pump oil, refer to below) must be much lower than the specified ultimate vacuum
of the pump.
Refer to Section 5.11.3 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 pump from the vacuum system.
2. Turn the gas-ballast control fully anti-clockwise (fully open) and operate the pump for at least 1 hour
(or overnight) to thoroughly purge the oil of contaminants.
3. Close the gas-ballast control.
4. Open the vacuum system isolation-valve and pump down to ultimate vacuum.
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Edwards and the Edwards logo are trademarks of Edwards Limited.
WARNING
4.6 respectively. Otherwise, open the vacuum system isolation-valve.
Section 4.2).
Section 2.2, make sure that this is not due to the system
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