Edwards nEXT nEXT85 - Interstage Connection; Purge Gas Connection; Recommended Purge Gas Flow; Connect the Purge Gas

Use applicable vacuum tubing and connectors to connect the NW25 ange of the
backing port to the backing pump. If necessary, use exible pipe or bellows to decrease
the transmission of the vibraon from the backing pump to the pump.
4.2.4 Interstage connecon
An interstage connecon is only possible using an 'i' nEXT pump to back the other pump.
1. Use applicable vacuum tube and connectors to connect the interstage port to the
vacuum system or to the outlet ange of the other turbo or compound
turbomolecular pump.
2.
Keep the inlet strainer in the interstage port only if you are sure that debris cannot
enter into the interstage port.
4.3 Purge gas connecon
4.3.1 Recommended purge gas ow
The recommended purge gas ow for typical applicaons is 25 sccm (0.42 mbar l s
-1
,
42 Pa l s
-1
). The ow protects the pump when you pump the oxygen in concentraons
more than 20% by volume.
The ow rate of the purge gas must be in a range given in Purge gas specicaon on
page 21. To limit the ow rate, use a ow controller or a pressure regulator and
calibrated ow restrictor. The PRX10 purge restrictor accessory is applicable for the
purpose. Refer to Accessories on page 101.
4.3.2 Connect the purge gas
Note:
The purge gas must comply with the specicaon given in Purge gas specicaon on
page 21.
1. To supply the purge gas to the pump, remove the plug installed in the purge port.
2. To install a vent port adaptor, refer to Accessories on page 101.
3.
Connect the purge gas supply to the vent port adaptor.
4.4 Electrical installaon
WARNING: ELECTRICAL INSTALLATION
Risk of injury or damage to equipment. Make sure that the electrical installaon of
the pump is in accordance with the regional and local codes and conforms to local
and naonal safety requirements. The pump must be connected to an applicable
power supply unit with an applicable earth (ground) point.
Make sure that qualied persons do the electrical installaon. Do the electrical
connecons of the pump aer the pump is installed on the vacuum system.
Do not remove the motor controller from the pump. The motor controller does not have
user-serviceable parts.
Page 41
B8G000880_D - Installaon