Edwards nEXT730D User Manual

If the LEDs do not light up as expected, or if the red or yellow LEDs begins to ash a
repea
ted sequence or if the red LED is lit, refer to Fault nding on page 96. If the bearing
LED is lit or ashing refer to Bearing monitoring and condioning system on page 106.
7.2 Vent opons, vent valve connecon and control
Note:
If manually venng the pump when it is at full rotaonal speed and the sub
sequent rate
of pressure rise is too high, the pump life may be reduced. When using the manual vent
valve supplied, it is recommended to either limit the vent or only open the vent valve
aer the pump speed has fallen to 50% of full rotaonal speed. Do not vent from the
backing line as this may lead to contaminaon. If venng into the vacuum system and
using an oil sealed rotary backing pump, select a point upstream of the pump, to prevent
oil back-streaming from the backing line. Table: Vent restrictor orice diameter if venng
the vacuum system chamber gives an indicaon of the appropriate orice size to be
ed to the vent-valve for given vacuum system volumes in order that the vent rate is
kept within the limits given in Vent gas specicaon and vent control data on page 30.
To maintain the cleanliness of the vacuum system, venng the pump (or vacuum system)
is recommended whenever switching the pump o.
7.2.1 Manual vent valve
Edwards recommends that the manual vent valve is opened only aer the pump speed
has fallen to 50% of full rotaonal speed.
A manual vent valve is supplied with the nEXT pump. It is not possible to accurately
control the rate of pressure rise using the manual vent valve so take care not to open it
too quickly.
7.2.2 TAV5 or TAV6 solenoid vent valve
The TAV solenoid valves can be purchased as accessories and come either pre-wired
with an auxiliary connector ed or as a bare-wire opon.
Both 'Normally Closed' and 'Normally Open' valves are available, refer to Accessories.
Venng may be accomplished by one of the following means, and by using the
procedure below:
▪ Use the TAV solenoid vent valve in the manual vent valve posion.
▪ Use the TAV solenoid vent valve connected to a convenient ange on the v
acuum
system.
▪ Use an alternave vent valve, with an appropriate restricon, connected to the
vacuum system.
When using the TAV vent valve, the pump may only be hard vented when it is at full
speed if the vacuum system has a volume of 5 litres or more.
If the volume of the vacuum system is less than 5 litres, incorporate a suitable vent
restrictor and vent the pump when it is at full speed, or use the controlled venng
opon. Table: Vent restrictor orice diameter if venng the vacuum system chamber
gives an indicaon of the appropriate orice size to be ed to the vent valve for given
08/2021 - ©Edwards Limited
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B8J200880_D - Operaon

Edwards nEXT730D Specifications

General

Brand	Edwards
Model	nEXT730D
Category	Water Pump
Language	English