3.6
Electrical installation
Always make the electrical connections to the EXT250M after it has been installed on your
vacuum system.
The EXC300M Controller provides the electrical supply to the EXT250M through the
pump-to-controller cable. Connect and lock the bayonet-connectors at the ends of the cable to the
mating connectors on the pump and the EXC300M Controller. Do not disconnect the cable while
the pump is operating, as this will cause an accident and damage the safety bearings (see Section
3.2.2).
The EXC300M Controller is designed to allow a pumping system to be configured in a variety of
ways, from a basic manually-operated system to a fully automatic system with remote control.
Refer to the instruction manual supplied with the EXC300M Controller to complete the electrical
installation.
3.7
Cooling
CAUTION
When you bake the EXT250M pump to above 70
o
C at the inlet-flange, you must cool the
pump by forced-air or water-cooling to prevent automatic shut-down of the pump by the
EXC Controller.
We recommend that, whenever possible, you cool the EXT250M pump by forced-air or
water-cooling, however if necessary you can use natural convection to cool the pump on certain
applications. Table 6 shows the acceptable cooling methods which you can use for different
applications.
If you use natural convection or forced-air to cool the pump, you must ensure that there is an
adequate supply of cooling-air to the pump.
EXT250M Turbomolecular Pump
19
