Automatic Vent Options; Normal Speed Setting; Electronic Braking - Edwards nEXT730D Instruction Manual

▪ Measured motor controller temperature
▪ Measured bearing temperature
The analogue output signal ranges from 0 to 10 V and is directly proportional to the
system parameter (refer to
Connect the analogue output to a suitable meter or indicator to display the appropriate
system parameter or connect it to the customer control equipment (for example, to
operate other components in the pumping system at preset values).
Only one system parameter can be monitored at a time using the analogue output.
However, it is easy to configure the controller to monitor a different system parameter
(refer to

3.3.5 Automatic vent options

The manufacturer's TAV vent valve can be connected directly to the motor controller.
The motor controller can provide a number of different venting options and can be
configured for both a normally closed and a normally open vent valve.
The motor controller can control the rate of venting. Using this feature the pump can be
vented from full rotational speed in a controlled manner that will not damage the pump
bearings. Once the pump rotational speed has dropped to below 50% of maximum
speed, it is safe to hard vent (open the vent valve fully).
There are many venting options available, including:
▪ Hard vent when rotational speed drops below 50% speed
▪ Controlled vent when above 50% speed and hard vent below 50% speed
▪ Hard vent immediately through a suitable restrictor.
Controlled venting gives the benefit of a quicker ramp down time by controlling the vent
rate through a single large orifice across the pump speed range. A full list of the venting
options is given in
In addition there is a feature that allows a delayed start of the nEXT pump. With this
feature, the vent valve can be closed before starting the pump. This allows the backing
pump to reduce the pressure in the vacuum system before starting the nEXT pump.
Both a TAV and a cooling fan can be controlled at the same time using the 'Y' cable
adaptor. No configuration is required.

3.3.6 Normal speed setting

The normal speed is a user-selectable parameter that can be set from 50% to 100% of
full rotational speed.
When the pump reaches normal speed, a signal is available on the normal pin of the
logic interface connector. This signal can be used to control the application since it
shows that pump speed, and therefore vacuum performance, has reached a specific
minimum level. The default setting is 80% of full rotational speed. Refer to
setting on page 70 for instructions on altering the normal speed setting.

3.3.7 Electronic braking

The pump has a user selectable electronic braking option that is disabled by default.
With this option disabled, the pump will draw power from the electrical supply
B8J200880_D
300812671_002_C3
B8J200880_D - Overview
Logic interface
Analogue signal options
Vent options, vent valve connection and control
on page 18).
on page 72).
Page 17
on page 76.
Normal speed
08/2021 - ©Edwards Limited