Edwards nEXT nEXT85 - Normal Speed Setting; Electronic Braking; Logic Interface

There is also a feature that allows a delayed start of the pump. With this feature, the
vent valve can be closed before starng the pump. This allows the backing pump to
decrease the pressure in the vacuum system before starng the pump.
With a ‘Y’ cable adaptor, a TAV and a cooling fan can be controlled at the same me. No
conguraon is necessary.
2.3.6 Normal speed seng
The normal speed is a user‑selectable parameter which can be set from 50% to 100% of
full rotaonal speed.
When the pump gets to normal speed, a signal is available on the normal pin of the logic
interface connector. The signal can be used to control the applicaon as it shows that
the vacuum performance (pump speed) is at a set level. The default seng is 80% of the
full rotaonal speed. Refer to Normal speed seng on page 62 for instrucons to
change the normal speed seng.
2.3.7 Electronic braking
The pump has a user‑selectable electronic braking opon which is disabled by default.
With the electronic braking opon disabled, the pump will take power from the
electrical supply during acceleraon and operaon.
When the pump decelerates it will coast down and power will not be returned to the
electrical supply.
The electronic braking opon can be enabled to decrease the pump deceleraon me
and to recover some energy from the pump. This can be done by returning the power
from the pump to the electrical supply. The rate at which the electrical energy is
returned to the supply is regulated to the voltages shown:
Voltage range Returned electronic braking voltage
Below 21.6 V d.c. (24 V d.c. -10%) Outside working range for pump
21.6 V d.c. to 26.4 V d.c. 24 V d.c. +10%
26.4 V d.c. to 38.4 V d.c. Electronic braking not funconal
38.4 V d.c. to 50.4 V d.c. 48 V d.c. +10%
Above 50.4 V d.c. (48 V d.c. +5%) Outside working range for pump
To get the fastest electronic braking mes, the returned power must go to somewhere,
such as:
▪
A supply capable to receive the returned power.
▪
Other devices that share the same electrical supply bus with the pump.
▪
An applicable 2 A load during the deceleraon of the pump.
2.4 Logic interface
The pump controller can be operated only through the logic interface. The signals on the
logic interface are of three types:
▪
Control inputs: Switch‑type signals that are used to control the pump
▪
Status outputs: To idenfy the status of the system
Page 14
B8G000880_D - Introducon