Edwards, nEXT Turbomolecular Pumps, nEXT240, nEXT300 and ...

B800-00-880 Issue B
4 Operation
WARNING
Do not operate the nEXT pump unless it is connected to your vacuum system. If you do, the pump
rotor can cause injury. The pump rotor rotates at very high speeds and the rotating blades might
not be visible.
Operation
Before operating the pump, it is worthwhile configuring the various Controller settings so that they are suitable for
your application.
If your system is designed to operate with Parallel control and monitoring, you will not have the facility to change
the majority of the Controller settings once the nEXT pump is installed on your system. The pump is supplied with
all settings at factory default values, as shown in Table 16. If you wish to change any of the Controller settings, make
sure you do this separately before installing the nEXT pump on your system.
To configure the nEXT pump you could use your own serial system. Section 4.1 details the commands that you will
need to configure the Controller. Alternatively you could use the Edwards TIC Turbo and Instrument Controller or TIC
Turbo Controller. Further information regarding this is detailed in Section 4.2.
Note: The standby speed may be adjusted using the button on the controller as described in Section 4.1.4.
If you intend to operate the nEXT pump with Parallel control and monitoring and you do not wish to reconfigure the
Controller settings, go straight to Section 4.3.
4.1 Configuring the nEXT pump using serial commands
Refer to Table 16 for a summary of the full set of serial commands, parameter ranges and factory defaults for each
setting. The following sections describe the settings in more detail.
4.1.1 Power limit setting
Table 21 shows the power limit setting options for the nEXT pumps. The pump is supplied to you with a default power
limit as shown. If this limit is not suitable for your application, you can change it to any value between the maximum
and minimum shown.
Table 21 - Power limit setting
Maximum value setting Minimum value setting Default power setting
200 W 50 W 160 W
Send the command as follows (where the 'd' characters represent the value in Watts that you are trying to set. For
example, if you want to set the limit to 90 W, type 90).
The reply you receive will be in the following format:
Command ! S 8 5 5 sp d d d cr
Reply S 8 5 5 sp r cr
The Power Limit Setting is now stored in memory within the nEXT pump.
To check what power limit is set, you can send a query as follows:
Command ? S 8 5 5 cr
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