Edwards nEXT nEXT85 - Motor Controller

adapter and purge restrictor to the purge port to control the ow rate of the purge gas
and to lter the gas supply. This can be used to opmise the performance of the pump,
for example with low molecular mass gases. Refer to Accessories on page 101.
A forced air-cooling kit and a water‑cooling block are available as oponal accessories to
cool the nEXT pump. Refer to Accessories on page 101.
Note:
The units used throughout this manual conform to the SI internaonal system of units of
measurement. Also throughout this manual, wherever ow rates are specied, the
abbreviaon 'sccm' is used to mean standard cm
3
min
-1
: this is a ow of 1 cm
3
min
-1
at an
ambient temperature of 0 °C and a pressure of 1013 mbar (1.013 x 10
5
Pa).
2.2 Motor controller
The motor controller has the drive electronics that control the pump operaon, the TAV
vent valve and the air cooler.
An auxiliary connector socket is given at the side of the motor controller where you can
plug in the TAV vent valve and the air cooler. Refer to Motor controller auxiliary
connector socket on page 28.
A USB port (Figure: Motor controller status informaon on page 46, item 9) is given
which is a service port to use with our nST PC soware using a standard micro‑USB
cable. This enables the pump to be congured, monitored and upgraded without
disconnecng from the 24 ‑ 48 V d.c. supply. This soware is available for download
from our Upgrade website: www.upgrades.edwardsvacuum.com
Currently, for the nST soware, a free license is necessary to use the soware. To get a
free license, obey the on‑screen instrucons, complete the user data form and send the
automacally generated email to us.
The controller has ve indicator LED's which signal the general status, operaon and
service status of the pump. The LEDs can be used for fault nding if a problem occurs.
Refer to Indicator LEDs on page 29.
The motor controller has built‑in safety features to prevent the pump from damage
during sustained high pressure or temperature.
▪ The electronics constantly monitors the temperature in the controller and the
temperature of the motor in the pump. If the controller or the motor gets too hot,
the controller decreases the power supplied to the pump motor and the pump
speed decreases. If the rotaonal speed of the pump decreases below 50% of the
full speed, the electronics can trip into a fail condion, depending on the system
conguraon. Refer to Timer on page 12.
▪
If the pump inlet pressure increases, the power supplied to the pump motor
increases to counteract the gas friconal load. When the built‑in maximum power
limit is reached, the speed of the pump starts to decrease. If the rotaonal speed
of the pump decreases below 50% of the full speed, the electronics can trip into
fail condion, depending on how the system has been congured. Refer to Timer
on page 12.
If the electrical supply fails, the controller uses the motor in the pump as a generator.
This means the pump has its own regenerave supply and a separate baery for
emergency power backup is not necessary. The regenerated energy maintains the
Page 11
B8G000880_D - Introducon