3.2.2
Protection of the safety bearings
You must take precautions to prevent the occurrence of the accidents listed in Table 1. If you do
not, the safety bearings may be damaged. We recommend that you take the following
precautions to prevent or limit damage to the safety bearings:
·
Use physical barriers to protect the pump-to-controller cable against damage or accidental
disconnection.
·
Fit a suitable vent-restrictor to the inlet of your vent-valve if you want to vent your system
when the pump speed is above 50% of full rotational speed. The vent and purge-ports of the
pump are fitted with vent-restrictors which limit the rate of pressure rise to a safe value, even
when the pump inlet-flange is blanked off.
·
Fit a solenoid operated vent-valve (see Section 3.4) and control the vent-valve with the
EXC300M Controller. The EXC300M Controller is supplied configured so that it opens the
vent-valve if the ‘Emergency’ or ‘Fail’ LEDs go on.
·
Construct your system so that it prevents the transmission of excessive mechanical shocks to
the EXT250M pump.
3.3
Connect the EXT250M to your vacuum system
WARNING
Install the pump in your vacuum system before you connect the EXC300M Controller.
This will ensure that the pump cannot operate and injure people during installation.
3.3.1
Inlet-screen
Do not remove the inlet-screen unless you can be sure that there is no danger of debris falling into
the pump. In order to avoid the danger of injury from the rotor blades, do not remove the
inlet-screen until you are ready to connect the pump to your system. If the inlet-screen is
removed, the pumping speed will increase by approximately 10%.
EXT250M Turbomolecular Pump
13
Figure 5 - Correct installation of the inlet-screen
1.
EXT250M inlet-flange
2.
Inlet-screen
