Edwards nEXT nEXT85 - Vent Options, Vent Valve Connection and Control; Manual Vent Valve; TAV5 Solenoid Vent Valve

Refer to Fault nding on page 86 if:
▪ LEDs do not illuminate
▪ Red or yellow LEDs ash in a repeated sequence
▪ Red LED is illuminated.
6.2 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 rate of increase
in pressure is too high, the pump life can decrease. When using the manual vent valve,
we recommend you to limit the vent or open the vent valve only aer the pump speed
decreases to 50% of the full rotaonal speed. Do not vent from the backing line to
prevent 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. The vent rate must be as per the limits given in Vent gas specicaon
and vent control data on page 20. Refer to Table: Vent restrictor orice diameter if
venng the vacuum system chamber on page 71 for the vent restrictor orice to be
installed on the vent valve.
To keep the cleanliness of the vacuum system, we recommend you to vent the pump (or
vacuum system) when seng the pump to o.
6.2.1 Manual vent valve
We recommend you to open the manual vent valve only aer the pump speed
decreases to 50% of the full rotaonal speed.
A manual vent valve is supplied with the pump. Precise controlling of the rate of
increase in pressure is not possible with the manual vent valve. Do not open the manual
vent valve too quickly.
6.2.2 TAV5 solenoid vent valve
The TAV5 solenoid valves is available as an accessory. The TAV5 solenoid valves comes as
pre-wired with an auxiliary connector installed or as a bare-wire opon.
'Normally Closed' and 'Normally Open' valves are available. Refer to Accessories on page
101.
Venng can be done by one of the methods that follow:
▪
Use the TAV5 solenoid vent valve in the manual vent valve posion.
▪
Use the TAV5 solenoid vent valve connected to a convenient ange on the vacuum
system.
▪
Use an alternave vent valve, with correct restricon, connected to the vacuum
system.
When using the TAV5 vent valve, the pump can be hard vented only 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, install a vent restrictor and vent
the pump when it is at full speed or use the controlled venng opon. Refer to Table:
Vent restrictor orice diameter if venng the vacuum system chamber on page 71 for
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B8G000880_D - Operaon