To Pump Condensable Vapours; To Decontaminate The Oil; Unattended Operation - Edwards E2M28 Instruction Manual

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.

5.5 To pump condensable vapours

Use gas-ballast (open the gas-ballast control) when there is a high proportion of
condensable vapours in the process gases:
1. Close the vacuum system isolation-valve.
2. Turn the gas-ballast control anti-clockwise to fully open and operate the pump for
30 minutes to warm the oil, this will help to prevent vapour condensation in the
pump.
3. Open the vacuum system isolation-valve and continue to operate the pump with
the gas-ballast control open.
After pumping condensible vapours, decontaminate the oil (if necessary), use the
procedure in

5.6 To decontaminate the oil

The oil in the pump should be clear. If the oil is cloudy or discoloured, it is contaminated
with process vapours.
1. Look at the condition of the oil in the oil sight-glass
pump on page
at step 2 below.
2. Close the vacuum system isolation-valve.
3. Turn the gas-ballast control fully anti-clockwise.
4. Operate the pump until the oil is clear.

5.7 Unattended operation

The pump is designed for unattended operation under the normal operating conditions
specified in
checking the pump at a regular interval of not more than 14 days; check the pump more
frequently if pumping high volumes of gas or if operating the pump with the gas-ballast
control open.
Single-phase motors are cooled by internal fans. These motors have a thermal overload
device. When the motor is too hot, the thermal overload device switches off the pump.
The thermal overload device has an automatic reset; when the motor cools down, the
device resets and the motor will restart.
When checking the pump, make sure that the pump is not going through a repetitive
cycle of thermal overload failures and automatic resets. If necessary, reduce the thermal
load from the pumped gases to prevent overheating of the pump.
A37310880_V - Operation
To decontaminate the oil on page
11). If the oil is cloudy or discoloured, continue with the procedure
Operating and storage conditions on page
Page 31
31.
(Figure: General view of the
12. However, we recommend