Edwards nEXT 55, Instruction Manual

Page: 13 / 116

2.4.2 Standby speed
In standby mode, the pump rotational speed is lower than the full rotational speed. The
default setting for standby speed is 70% of the full speed.
To operate the pump at standby speed, it must be in the start condition.
If operating the pump at maximum speed at all times is not necessary for the
application, use the standby speed feature rather than setting the pump to off. You can
use the standby speed feature for tuning the vacuum system or as a power saving option
for the system.
The standby speed is a user
‑
selectable value. Refer to Standby speed setting on page 65.
2.4.3 Timer
When the pump is started, an internal timer starts automatically in the motor controller.
The default timer setting is 8 minutes.
If the pump fails to reach 50% of full rotational speed in the timeout period, the motor
controller will signal a fail and decelerate the pump to rest. This feature prevents the
motor controller from driving the pump at maximum power for a long time. The pump
can fail to reach 50% speed if the gas load is too high (for example if there is a leak in the
system), if the backing pump fails or if the pump is too hot.
The timeout period is user
‑
selectable (refer to Timer setting and options on page 66). If
slow ramp
‑
up of the pump is necessary for the application, extend the timeout period.
The timer is permanently enabled for ramp
‑
up.
If the rotational speed of the pump decreases below 50% of the full speed, the pump
time can be set to recover rather than trigger a fail condition. The timer starts
immediately when the rotational speed of the pump decreases below 50% of the full
speed. If the rotational speed of the pump increases above 50% during the timeout
period, the timer will reset. If the rotational speed of the pump does not recover by the
end of the timeout period, the motor controller will trigger a fail condition and
decelerate the pump to rest.
The timer function is enabled when the pump is shipped. You can disable the timer
function. If the timer function is disabled, the pump will fail and decelerate to rest
immediately when the rotational speed of the pump decreases below 50%.
2.4.4 Analogue output
The pump controller gives an analogue output for monitoring five parameters of the
system:
▪ Measured pump rotational speed (default condition)
▪ Measured link power
▪ Measured motor temperature
▪ Measured controller temperature
▪ Measured rotor power
The range of the analogue output signal is from 0 to 10 V and is directly proportional to
the system parameter. Refer to Logic interface on page 15.
07/2021 - ©Edwards Limited Page 13 B8G000880_E
B8G000880_E - Introduction