Edwards nEXT 55, Инструкция по эксплуатации, Страница: 82 / 116

▪ receiving a stop command or a detecting a fault condition and
▪ opening of the vent valve.
The delay allows time for gauges, valves and other equipment to set to off before
venting occurs.
The green indicator LED on the motor controller will extinguish as rotational speed drops
below normal speed. At very low speeds, the yellow indicator LED flashes. The yellow
indicator LED extinguishes when the pump has stopped.
The deceleration time can be improved by using the electronic braking feature. Refer to
Electronic braking options on page 68.
6.8 Operation at extreme conditions
6.8.1 Operation with high inlet pressure
If the pump inlet pressure increases, the power supplied to the pump motor will
increase to counteract the gas frictional load.
The pump rotational speed will stay constant until the peak power level is reached. After
the peak power level, the speed of the pump will start to decrease.
If the pump speed decreases below 50% of full rotational speed, the timer will start (if it
is enabled). If the speed does not recover to more than 50% speed before the timeout
period expires, the pump will stop and display a fail signal. If the timer is disabled, the
pump will stop immediately and display a fail signal if the speed decreases below 50% of
the full rotational speed. Refer to Electrical data on page 24 for the maximum power
delivered to the pump. Refer to Table: Pump performance data for maximum permitted
inlet pressure.
6.8.2 Operation 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 rotational speed if
it is too hot.
If the pump speed decreases below 50% of the full rotational speed, the timer will start
(if it is enabled). If the speed does not recover to more than 50% speed before the
timeout period expires, the pump will stop and display a fail signal. If the timer is
disabled, the pump will stop immediately and display a fail signal if the speed decreases
below 50% of the full rotational speed. Refer to Table: Operating and storage conditions
for pump operating ranges. Refer to Cooling on page 59 for advice on pump cooling.
6.8.3 Protection against over-speed
Control software in the motor controller controls the pump rotational speed and
prevents the operation of the pump more than its normal full rotational speed.
If the control software fails, the motor controller has a built
‑
in safety circuit that checks
if the pump is operating at over
‑
speed. If an over
‑
speed condition is detected, the motor
controller automatically stops the power to the pump motor and slows the pump to a
stop. The motor controller signals a fail condition if over
‑
speed is detected.
07/2021 - ©Edwards Limited Page 82 B8G000880_E
B8G000880_E - Operation