Operational Features; Power Limit Setting - Edwards nEXT730D Instruction Manual

CAUTION:
Do not disconnect the pump from the electrical supply until the pump has stopped
completely.
There is an auxiliary connector socket in front of the motor controller where the TAV
vent valve and the Air cooler can be plugged into. Refer to
connector socket
There is a USB port (item 9) which is a service port to be used with the Edwards nST2 PC
software, using a standard micro-USB cable. This will enable the pump to be configured,
monitored and upgraded without disconnecting from the 48 V d.c. supply. This software
is available for download from the Edwards' Upgrade website:
www.upgrades.edwardsvacuum.com.
The motor controller has seven indicator LEDs that signal the general status, operation,
service status of the pump, CAN and serial communication and bearing service status.
The LEDs can be used for fault finding if a problem should occur.
The motor controller has a number of built-in safety features to protect the nEXT pumps
from damage in the event of sustained high pressure and temperature.
▪ The electronics constantly monitors the temperature inside the motor controller
and the temperature of the bearing inside the pump. If either part becomes too
hot, the motor controller reduces the power supplied to the pump motor and the
pump speed will drop. If the pump rotational speed reduces below 50% of full
speed, the electronics may trip into a Fail condition, depending on the system
configuration.
▪ If the pump inlet pressure increases, the power supplied to the pump motor
increases to counteract the gas frictional load. However, when the built‑in
maximum power limit is reached, the speed of the pump will start to drop. If the
pump rotational speed falls below 50% full speed, the electronics may trip into Fail
condition, depending on how the system has been configured. Refer to Time
on page 16.
▪ In the event of an electrical supply failure, the controller uses the motor within the
pump as a generator. This means the nEXT pumps have their own regenerative
supply and do not require a separate battery for emergency power backup. The
regenerated energy is used to maintain the electrical supply to the controller and
any vent valve or fan attached to the controller connector until the pump speed
falls to below 50% of full rotational speed: this will ensure that the vent valve
remains shut until below 50% of full rotational speed and will prevent the pump
from venting at full speed. It also ensures that the serial link and signals on the
parallel interface remain active until the pump speed falls below 50%.

3.3 Operational features

In addition to the basic start and stop commands, the nEXT pumps have several other
features that allow pump operation to be tailored to a particular application.

3.3.1 Power limit setting

Select the maximum power that will be drawn by the pump. The more power supplied,
the quicker the pump will accelerate to reach full speed.
B8J200880_D
300812671_002_C3
B8J200880_D - Overview
on page 47.
Page 15
Motor controller auxiliary
08/2021 - ©Edwards Limited
Timer