Rockwell Automation 1440-VST02-01RA XM-120 Eccentricity Module - Manual (Page 9)

1 Publication GMSI10-UM010C-EN-P - May 2010
Chapter
1
Introduction
This chapter provides an overview of the XM-120 Eccentricity module. It also
discusses the components of the module.
Introducing the Eccentricity
Module The XM-120 Eccentricity module is a 2-channel eccentricity monitor. It is a
member of the Allen-Bradley™ XM
®
Series, a family of DIN rail mounted
condition monitoring and protection modules that operate both in stand-alone
applications or integrate with Programmable Logic Controllers (PLCs) and
control system networks.
Eccentricity is the measure of the amount of bow in a rotor. The lower the
eccentricity value the more straight the shaft. Rotor bow can be a fixed
mechanical bow, or it can be a temporary bow caused by uneven thermal
heating or simply by the weight of the rotor (gravity bow).
The Eccentricity module is suitable for virtually all types of rotating and
reciprocating machinery where rotor bow must be measured prior to or during
startup. It accepts input from non-contact eddy current probe systems to
provide peak-to-peak eccentricity, maximum instantaneous DC voltage (max
gap), minimum instantaneous DC voltage (min gap), and instantaneous DC
voltage (gap) measurements. In addition to the transducer inputs, the module
can accept one tachometer input to provide speed measurement, which can, if
desired, be used to disable eccentricity alarms after startup.
For information about See page
Introducing the Eccentricity Module 1
Eccentricity Module Components 2
Using this Manual 3
IMPORTANT
This manual only describes how to install and use the
XM-120 Eccentricity module. For information about the
dynamic measurement and low frequency dynamic
measurement modules, refer to the XM-120/121 Dynamic
Measurement Module User Guide.