Edwards nEXT730 - Page 93

B8J200880_E - Operation
Page 92
Option
number
Description of vent function
5
In a fail condition, vent valve fully opens immediately. If a stop
command is received, controlled venting from 100% to 50% full
rotational speed and then vent valve opens fully below 50%.
6
Vent valve fully opens immediately for either a stop command or a fail
condition.
7
Same as option 6
8
Auxiliary output is permanently energised (Fan).
§
9
Do not use
10
Auxiliary output is permanently de-energised (Fan).
11
Do not use
12
Do not use
13
Do not use
14
Vent valve opens fully below 50% full rotational speed for a stop
command.
15
Controlled venting from 100% to 50% full rotational speed and then
vent valve opens fully below 50% for a stop command.
*
This is the factory default setting for Vent Option 1.
§
This is the factory default setting for Vent Option 2 to enable cooling fan behaviour.
Table 20 Valve types
Option number
Description of valve type
0
Normally open vent valve
*
1
Normally closed vent valve
*
This is the factory default setting for Valve 1 type and Valve 2 type.
When the pump is shipped, the controller is configured with the factory default Vent
option 1 set to 0 and the Valve 1 type set to 0, as detailed in Table: Vent valve options
and Table: Valve types. The controller can be configured to one of the other venting
options provided commands can be sent via the serial interface, an Edwards TIC Turbo
and Instrument Controller, TIC Turbo Controller, or the Edwards nST2 PC software can be
used via the USB serial port.
If the valve type is set to normally open, the controller only energises or shuts the TAV
solenoid valve when it receives a start command. Prior to that, the valve will be in the
‘open’ vent state. If the vacuum system is a large system, allow the backing pump to
reduce the pressure in the system to an acceptable level before starting the nEXT pump.
In this case, send a command via the serial interface to close the vent valve before
sending a start command – this is known as a delayed start.
If the valve type is set to normally closed and either vent options 14 or 15 are used, the
controller will ensure that the TAV solenoid valve will only ‘open’ upon receipt of a stop
command. Therefore there is no need to send the delayed start command.
If the nEXT pump is being controlled with an Edwards TIC Turbo and Instrument
Controller or TIC Turbo Controller, the TAV solenoid valve can be driven from the TIC.
Refer to the TIC Instruction Manuals for more information.