1
INTRODUCTION
1.1
Scope and definitions
This manual provides installation, operation and maintenance instructions for the BOC
Edwards EXT250M Turbomolecular Pump. You must use the EXT250M as specified in this
manual.
The EXT250M pump is designed for use with a BOC Edwards EXC300M Controller. Read this
manual and the EXC300M Controller instruction manual before you install or operate the
equipment. The EXC300M Controller instruction manual contains details of how to set up a
pumping system and how to control accessories such as an air-cooler, vent-valve and bakeout
band.
Important safety information is highlighted as WARNING and CAUTION instructions; you
must obey these instructions. The use of WARNINGS and CAUTIONS is defined below.
WARNING
Warnings are given where failure to observe the instruction could result in injury or death
to people.
CAUTION
Cautions are given where failure to observe the instruction could result in damage to the
equipment, associated equipment and process.
In accordance with the recommendations of EN61010, the following warning symbols may
appear on the pump or its accessories:
Caution - refer to accompanying documents.
Caution - risk of electric shock.
Caution - hot surface.
Protective conductor terminal.
The units used throughout this manual conform to the SI international system of units of
measurement. Where purge flow rates are specified, the abbreviation ‘sccm’ is used to mean
‘standard cm
3
min
-1
‘: this is a flow of 1 cm
3
min
-1
at an ambient temperature of 0
o
C and a
pressure of 1013 mbar (1.013 x 10
5
Pa).
EXT250M Turbomolecular Pump
1
