Edwards E2MO.7 - Start-Up; To Achieve Ultimate Vacuum

5.3 Start-up
WARNING:
Ensure that the system design does not allow the exhaust pipeline to be blocked
If the oil is contaminated, or if the pump temperature is below 12 °C (53.6 °F), or if the
electrical supply voltage is more than 10% below the lowest voltage specied for the
pump, the pump may operate at a reduced speed for a few minutes. If the pump
connues 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
automacally 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 Check the oil level on page 28.
2.
Turn the gas-ballast control to the required posion (refer to Gas-ballast control on
page 23).
3.
Switch on the electrical supply to the pump.
4. Check that the oil-level in the sight-glass drops slightly (3 to 5 mm) aer 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 ulmate vacuum, pump condensable vapours or decontaminate the
pump oil, refer to the procedures in To achieve ulmate vacuum on page 24, To
pump condensable vapours on page 25 and To decontaminate the oil on page 25
respecvely. Otherwise, open the vacuum system isolaon-valve.
5.4 To achieve ulmate vacuum
If the pump does not achieve the performance specied in Performance on page 12,
make sure that this is not due to the system design before you contact supplier or us for
advice, In parcular, the vapour pressure of all materials used in the vacuum system
(including pump oil) must be much lower than the specied ulmate vacuum of the
pump.
Refer to The pump fails to achieve specied performance (failure to reach ulmate
vacuum) for a list of possible causes for failure to achieve the specied performance,
note however that the most common causes are:
▪
Pressure measurement technique or gauge head is unsuitable or the gauge head is
faulty.
▪
Use of an oil other than the recommended oil and the vapour pressure of the oil is
higher than the specied ulmate vacuum of the pump.
Use the following procedure to achieve ulmate vacuum:
1.
Isolate the pump from the vacuum system.
2.
Turn the gas-ballast control fully an-clockwise (fully open) and operate the pump
for at least 1 hour (or overnight) to thoroughly purge the oil of contaminants.
Page 24
A37132880_F - Operaon