Manual Shut Down - Edwards GXS Series Instruction Manual

Evacuating the chambers back‑filled with Argon
▪ For small chambers less than 2 m
in under 2 minutes, the chamber evacuation is short enough not to cause a
problem when pumping at full speed.
▪ For evacuating chambers between 2 m
speed should be set at 80 Hz until the pressure is below 20 mbar.
▪ For evacuating chambers larger than 25 m
information.
Note:
For prolonged operation (greater than 45 minutes, above 20 mbar and/or the
chambers in excess of 25 m
determine the actual requirement. Contact us for more information.
Shaft seal purge
Nitrogen or the Clean Dry Air (CDA) purge is preferred as it gives a maximum headroom
on the critical clearances. Argon can be used as shaft seal purge at 80 Hz and 110 Hz,
following the above guidelines for continuous operation and pump down of chambers.

4.5 Manual shut down

WARNING:
If the dry pumping system is shut down and not isolated from the electrical supply,
do not disconnect the PDT or release the control from the PDT or front panel. This
may result in the dry pumping system being started by another module.
WARNING:
Do not remove the inlet connections until the pump has been allowed to stop
rotating and the power has been isolated. The pump can take up to three minutes to
completely stop.
CAUTION:
If the pump is stopped without the gas purge cycle on processes that have
condensable or solid by‑products then the pump may not restart.
CAUTION:
For applications pumping liquids or condensible gases: If the pump is switched off
straight after the process then the liquids may remain trapped in the pump. These
liquids can corrode the pump mechanism while the dry pumping system is switched
off for extended periods and may prevent the pump from starting again. For these
applications, we recommend carrying out a Smart Stop with Stop Time set to the
maximum 3600 seconds. Once the pump has stopped, seal the inlet and exhaust to
prevent migration of liquid/condensable back into the pump mechanism.
The dry pumping system has two manual shut down modes: Fast and Auto.
M58800880_H - Operation
3
(70 cft) or if chamber pressure reaches 20 mbar
3
3
(885 cft)), an application review must be done to
Page 59
3
(70 cft) and 25 m (885 cft), the pump
3
(885 cft), contact us for more