Edwards nEXT200200 - Alternative Valve Connected to the Vacuum System; Cooling; Introduction

Opon number
Descripon of the v
ent funcon
6.7
Vent valve fully opens immediately for the Stop command or
Fail.
When the pump is shipped, the controller is set to the factory default vent opon 0,
refer to Table: Vent opons on page 53. You can congure the controller to one of the
other vent opons. Commands can be sent through the serial interface or the
manufacturer's TIC Turbo and Instrument Controller or Turbo Controller.
The controller only operates (shuts) the TAV solenoid valve when it receives a start
command. Before the controller operates (shuts) the TAV solenoid valve, the valve will
be in the 'open' vent state. If the vacuum system is a large system, let backing pump
decrease the pressure in the system to an acceptable level before you start the pump.
Send a command through the serial interface to close the vent valve before you send a
start command. This is known as a delayed start.
If you control the pump with the manufacturer's TIC Turbo and Instrument Controller or
TIC Turbo Controller, the TAV solenoid valve can be operated from the TIC. Refer to the
TIC Instrucon Manuals for more informaon.
4.9.4 Alternave valve connected to the vacuum system
If you use dierent vent valve, make sure that the applicable vent restrictor is installed in
the vacuum system to limit the rate of increase in pressure. Refer to Table: Vent
restrictor orice diameter (with atmospheric pressure at the inlet of the vent valve) on
page 54 for informaon about the sizes of vent restrictor. If the applicable vent restrictor
is not installed, open the vent valve only when the speed of the pump decreases to 50%
of the full rotaonal speed.
Table 17 Vent restrictor orice diameter (with atmospheric pressure at the inlet of the vent
valve)
Vacuum system volume (litres) Orice diameter (mm)
< 20
£ 1.0
< 10
£ 0.7
< 5
£ 0.5
< 2
£ 0.35
4.10 Cooling
4.10
.1 Introducon
CAUTION: PUMP COOLING
Risk of damag
e to equipment. Make sure that the pump is suciently cooled to
prevent the damage to the rotor and bearing.
When you use an alternave conguraon (other than the manufacturer's standard
cooling accessories) to cool the pump, make sure that the cooling is not directed or
ducted onto the pump controller.
Page 54
B85200880_D - Ins
tallaon