Instruction manual

EXT Split Flow Compound Turbomolecular Pumps

OPERATION

PAGE

Issue F 20 Mar 07

4.2 Shut-down

Note: In an emergency only, open the vent-valve quickly to decelerate the pump rotor in the shortest possible

time.

Use the procedure below to shut down a basic, manually-controlled pumping system with a manual vent-

valve and an EXDC Controller. Refer to the EXC Controller Instruction Manual when using an EXC

Controller.

1. Close the valve in the backing-line connecting the EXT Split Flow pump to the backing-pump.

2. Switch off the backing-pump.

3. Switch off the power supply to the EXT Split Flow Pump.

4. When the EXT Split Flow Pump rotational speed has fallen to 50% of full rotational speed, turn the

manual vent-valve anti-clockwise to open it. Ensure that the rate of pressure rise does not exceed

the allowed rate of pressure rise, otherwise you can damage the pump: refer to Section 3.4.

5. If water-cooling is in use, turn off the cooling-water supply and/or turn off the power to the air

cooler.

4.3 Safety interlocks and control system

The pump protection and safety interlock features are listed below. Refer to the instruction manual

supplied with the controller for a full description of these features.

4.3.1 EXDC Controllers

• The EXDC Controller monitors the temperature of the EXT Split Flow Pump and the electrical

power consumption of the pump. If the EXDC Controller detects excessive power consumption

or temperature, the rotational speed of the pump motor is reduced until the power and

temperature return to normal.

4.3.2 EXC Controllers

• The EXC Controller monitors the temperature of the EXT Split Flow Pump and the electrical

power consumption of the pump. If the EXC Controller detects excessive power consumption or

temperature, the rotational speed of the pump motor is reduced until the power and temperature

return to normal.

• If the rotational speed is reduced to 50% of nominal speed, then power is removed (or after a user

defined time delay) and the FAIL LED on the EXC Controller lights.

• If pump rotational overspeed is detected by the EXC Controller, the pump is stopped immediately

and the FAIL LED on the EXC Controller lights.

If the FAIL LED lights, switch off the backing-pump immediately and vent the EXT Split Flow Pump. Once

the EXT Split Flow Pump has stopped, rectify the cause of the failure (refer to Section 5.5), press the

EXC Controller Start/Stop button to reset the Fail condition, and restart the EXT Split Flow Pump. If the

pump is hot, allow sufficient time for it to cool before you restart it.

Note: Any references to LED’s and buttons do not apply to OEM versions of the EXC Controller i.e. EXC100L

or EXC100.

WARNING

Do not remove the EXDC Controller/EXC Controller cable from the pump until the

pump is completely at rest. To do so could expose personnel to hazardous voltage and

potentially damage the EXDC/EXC Controller.