Unitronics electric UM2B, User Manual

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APPENDIX D.- GLOSSARY
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Diagnosis
Deduction of the nature of a failure based on the symptoms detected.
Dielectric absorption.
The property of dielectrics to regain some charge following the removal of
momentary short-circuits. The dielectric acts as though throughout the charging
period it had become impregnated with a charge that remains during and after the
discharging period. This charge emanates again from the dielectric, causing a
voltage to reappear.
The explanation of this is due to the movement of dipoles and mobile ions in a
dielectric material exposed to an electrical field. It is a measure of the quantity of
impurities present inside the dielectric.
Dielectric rigidity or breakdown potential
Measurement of the resistance of a dielectric to dielectric rupture under the influence
of strong electrical fields, normally expressed in volts per centimeter.
Equipment
Complex unit of higher order made up of assemblies , components and parts , grouped
to form a functional system. Equivalent to the term machine .
Emergency Maintenance
Corrective maintenance required to avoid serious consequences.
Failure
Loss of the capacity of an item to perform its specific function. Equivalent to the
term breakdown .
Fuse
Device protecting apparatus against overload and short-circuit conditions. It contains
a small cross-section
conductor that melts when subjected to an excessively intense
current.
Ground
Point of zero potential. Not to be confused with mass.
History file
Record of events, breakdowns, repairs and actuations in general concerning a given
item .
Installation
System made up of items that form a functional production or service unit.