Edwards nEXT nEXT85 - Operation at Extreme Conditions; Operation with High Inlet Pressure; Operation at High Temperatures

The system can be vented in accordance with the advice given in Vent opons, vent
valve connecon and control on page 68.
CAUTION: RATE OF INCREASE IN PRESSURE
Risk of damage to equipment. Do not open a manual vent valve unl the pump
rotaonal speed decreases below 50%, otherwise the rate of increase in pressure can
be too high, which can damage the pump. In an emergency, open the vent valve
quickly to decelerate the pump rotor in the shortest possible me.
If using the motor controller to control a TAV solenoid valve, there is a 2‑second delay
between:
▪
receiving a stop command or a detecng a fault condion and
▪
opening of the vent valve.
The delay allows me for gauges, valves and other equipment to set to o before
venng occurs.
The green indicator LED on the motor controller will exnguish as rotaonal speed drops
below normal speed. At very low speeds, the yellow indicator LED ashes. The yellow
indicator LED exnguishes when the pump has stopped.
The deceleraon me can be improved by using the electronic braking feature. Refer to
Electronic braking opons on page 64.
6.8 Operaon at extreme condions
6.8.1 Operaon with high inlet pressure
If the pump inlet pressure increases, the power supplied to the pump motor will
increase to counteract the gas friconal load.
The pump rotaonal speed will stay constant unl the peak power level is reached. Aer
the peak power level, the speed of the pump will start to decrease.
If the pump speed decreases below 50% of full rotaonal speed, the mer will start (if it
is enabled). If the speed does not recover to more than 50% speed before the meout
period expires, the pump will stop and display a fail signal. If the mer is disabled, the
pump will stop immediately and display a fail signal if the speed decreases below 50% of
the full rotaonal speed. Refer to Electrical data on page 22 for the maximum power
delivered to the pump. Refer to Table: Pump performance data on page 30 for maximum
permied inlet pressure.
6.8.2 Operaon at high temperatures
Temperature sensors in the pump mechanism and electronics are monitored by an
internal system. If the system detects that internal temperatures are too high, the power
supplied to the pump motor is decreased. The pump cannot keep full rotaonal speed if
it is too hot.
If the pump speed decreases below 50% of the full rotaonal speed, the mer will start
(if it is enabled). If the speed does not recover to more than 50% speed before the
meout period expires, the pump will stop and display a fail signal. If the mer is
disabled, the pump will stop immediately and display a fail signal if the speed decreases
Page 78
B8G000880_D - Operaon