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

When operating the pump with the gas‑ballast control open, there will be an increased
rate of oil loss from the pump. Ideally, a mist filter and oil return kit should be used on
clean applications.

5.3 Start-up

WARNING:
Do not block the pump outlet or allow the outlet pressure to rise above 1.5 bar
absolute. 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
2. Turn the gas-ballast control to the required position (refer to
page
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
pump condensable vapours on page 31
respectively. Otherwise, open the vacuum system isolation-valve.

5.4 To achieve ultimate vacuum

If the pump does not achieve the performance specified in Performance, make sure that
this is not due to the system design before you contact supplier or us for advice, In
particular, the vapour pressure of all materials used in the vacuum system (including
pump oil) must be much lower than the specified ultimate vacuum of the pump.
Refer to
vacuum) on page 39
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 specified ultimate vacuum of the pump.
Use the following procedure to achieve ultimate vacuum:
1. Isolate the pump from the vacuum system.
A37310880_V - Operation
29).
The pump fails to achieve specified performance (failure to reach ultimate
for a list of possible causes for failure to achieve the specified
Check the oil level on page
To achieve ultimate vacuum on page
and To decontaminate the oil on page 31
Page 30
34.
Gas-ballast control on
30, To