© Edwards Limited 2007. All rights reserved.
Page 51
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Operation
A419-00-880 Issue F
5
Operation
5.1
Introduction
CAUTION
The flow switch is set to 12 slm and therefore provides an indication that a flow in excess of 12 slm is present,
but gives no guarantee that there is sufficient flow to prevent condensation or to provide sufficient dilution of
the process gas to ensure pump reliability.
The flow switch is not a guaranteed interlock. To ensure correct, reliable operation of the pump the system
installer should fit appropriate, interlocked hardware to ensure correct nitrogen purge flow and monitoring.
CAUTION
If the electrical supply to the EPX pump fails for up to one second, the pump will continue to run once the power
is returned.
CAUTION
If the electrical supply to the EPX pump fails for only a few seconds, the pump will continue to operate normally
provided the run signal on the interface is maintained.
WARNING
Do not operate the pump when the exhaust pipeline is restricted or blocked. If you do, the EPX
pump can generate pressures up to 16 bar (1.6 x 10
6
Pa) and be damaged.
WARNING
Inlet and exhaust temperatures can exceed 65°C in extreme operating conditions.
WARNING
The EPX N series of pumps must be purged for 30 minutes with the nitrogen purge gas flowing
before pumping process gas. This must be done with the pump running to allow it to warm up to
its full operating temperature.
WARNING
There are no user serviceable parts within the EPX pump. Metal covers must not be removed from
the pump; to do so may cause damage to the pump and injury to personnel and would invalidate
the declaration of conformity and the warranty. Qualified Edwards service personnel should allow
4 minutes after the isolation of power before removing any covers.