Operation; Before Starting The Pump; Close The Vent Valve; Pre-Start Sequence - Edwards nEXT730D Instruction Manual

7. Operation

7.1 Before starting the pump

Before starting the pump the vent valve must be closed and pre-start sequence
completed.

7.1.1 Close the vent valve

The vent valve can be closed manually, by using the customer control system or by TAV
solenoid valve.
1. If using a manual vent valve, turn it clockwise to close it.
2. If using the customer control system to drive a vent valve, make sure that the vent
valve is closed.
3. If driving a TAV solenoid valve from the motor controller, the TAV valve will
automatically shut when the pump is started.
4. If using the TIC to operate the vent valve, refer to
page 84.
Note:
The backing pump and nEXT pump can be started at the same time. The nEXT
pump will not be damaged and can operate as an effective baffle, however if the
vacuum system is large (100 litres or larger) it will be more efficient to allow the
backing pump to reduce system pressure to 10 mbar before starting the nEXT
pump. In this case it will be necessary to close the vent valve in advance of starting
the backing pump.
When using the motor controller to control a TAV solenoid valve and operating with
parallel control and monitoring, the valve cannot be shut in advance of starting the nEXT
pump because the facility to send the appropriate serial command is not available. If the
facility to send serial commands is available a delayed start can be performed. Refer to
Delayed start with serial control

7.1.2 Pre-start sequence

Complete the pre-start sequence to check that the pump is ready for operation.
Note:
If the motor controller has been configured to drive a fan, the fan will automatically start
when power is supplied to the nEXT pump.
1. Turn on the appropriate cooling device (fan or cooling water supply).
2. Start the backing pump.
3. Switch on the power supply to the pump. Check that the three normal, status and
alarm LEDs on the motor controller light up for approximately 0.5 seconds and
then extinguish.
4. Check that the bearing LED is off.
B8J200880_D
300812671_002_C3
B8J200880_D - Operation
on page 80.
Page 75
Operation with a TIC or TAG
08/2021 - ©Edwards Limited
on