Maintenance Technology April 2017 - 28

PREDICTIVE STRATEGIES

Add
Electrical
Motor
Testing to

Your PdM
Toolkit
This predictive approach
offers reliability benefits
that time-based
maintenance can't.

NUMEROUS STUDIES have tried to
establish guidelines for creating plant
reliability and efficiency. Depending
on which research is cited, the bottom
line is that between 65% and 75% of all
motor failures are mechanical in nature.
For that reason, vibration analysis, a
cornerstone of any predictive-maintenance (PdM) program, would appear to
provide the "biggest bang for the buck"
in pinpointing possible problems. Still,
while an aggressive vibration-analysis
program may accurately predict most
mechanical issues, it can't diagnose
the 25% to 35% of motor failures that
are due to electrical weaknesses and
faults. That's why electrical testing
is so important.
To put it simply, the insulation
system within a motor is the unit's
"heart"-and nothing but a series of
electrical tests can fully evaluate the
health and integrity of that heart.
Comprehensive evaluation involves

28 |

MAINTENANCE TECHNOLOGY

the use of static-testing and dynamicmonitoring technologies. To understand the benefits, it's important to
know why and how motors degrade.

Electrical testing of
a site's motors puts
personnel in the
reliability driver's seat.
Motor degradation
Various factors, including the initial
quality of a motor's insulation, affect
the pace at which it degrades. Since
heat is the main enemy of all insulation
materials, maintaining a cool, dry
environment will increase motor life.
Many things contribute to excessive
heat. Typically, the situation is acerbated by a combination of issues that

individually wouldn't create a problem.
High ambient temperature, numerous
restarts, starting under heavy loads,
slight misalignment, some unbalance
with the supply voltage, and contamination, all contribute to the heat a motor
experiences.
Another issue affecting the life of a
motor's insulation system is starting
and stopping. In fact, most plant-floor
personnel have, at some point in their
careers, heard the old saying that "if
you don't want your motor to fail, don't
start it, and if it's running, don't stop it."
Startup and, to some extent,
shutdown of a motor, are generally
the most stressful times in the unit's
life. Contactor and breaker "bounce"
at startup can generate voltage spiking
four or five times greater than the
operating voltage. The initial in-rush
of AC voltage, pushed by as much as
eight or 10 times the nameplate current,
"attacks" the insulation and greatly
APRIL 2017



Table of Contents for the Digital Edition of Maintenance Technology April 2017

Maintenance Technology April 2017 - 1
Maintenance Technology April 2017 - Cover1
Maintenance Technology April 2017 - Cover2
Maintenance Technology April 2017 - 1
Maintenance Technology April 2017 - 2
Maintenance Technology April 2017 - 3
Maintenance Technology April 2017 - 4
Maintenance Technology April 2017 - 5
Maintenance Technology April 2017 - 6
Maintenance Technology April 2017 - 7
Maintenance Technology April 2017 - 8
Maintenance Technology April 2017 - 9
Maintenance Technology April 2017 - 10
Maintenance Technology April 2017 - 11
Maintenance Technology April 2017 - 12
Maintenance Technology April 2017 - 13
Maintenance Technology April 2017 - 14
Maintenance Technology April 2017 - 18
Maintenance Technology April 2017 - 19
Maintenance Technology April 2017 - 20
Maintenance Technology April 2017 - 21
Maintenance Technology April 2017 - 15
Maintenance Technology April 2017 - 16
Maintenance Technology April 2017 - 17
Maintenance Technology April 2017 - 18
Maintenance Technology April 2017 - 19
Maintenance Technology April 2017 - 20
Maintenance Technology April 2017 - 21
Maintenance Technology April 2017 - 22
Maintenance Technology April 2017 - 23
Maintenance Technology April 2017 - 24
Maintenance Technology April 2017 - 25
Maintenance Technology April 2017 - 26
Maintenance Technology April 2017 - 27
Maintenance Technology April 2017 - 28
Maintenance Technology April 2017 - 29
Maintenance Technology April 2017 - 30
Maintenance Technology April 2017 - 31
Maintenance Technology April 2017 - 32
Maintenance Technology April 2017 - 33
Maintenance Technology April 2017 - 34
Maintenance Technology April 2017 - 35
Maintenance Technology April 2017 - 36
Maintenance Technology April 2017 - 37
Maintenance Technology April 2017 - 38
Maintenance Technology April 2017 - 39
Maintenance Technology April 2017 - 40
Maintenance Technology April 2017 - 41
Maintenance Technology April 2017 - 42
Maintenance Technology April 2017 - 43
Maintenance Technology April 2017 - 44
Maintenance Technology April 2017 - 45
Maintenance Technology April 2017 - 46
Maintenance Technology April 2017 - 47
Maintenance Technology April 2017 - 48
Maintenance Technology April 2017 - 49
Maintenance Technology April 2017 - 50
Maintenance Technology April 2017 - 51
Maintenance Technology April 2017 - 52
Maintenance Technology April 2017 - 53
Maintenance Technology April 2017 - 54
Maintenance Technology April 2017 - 55
Maintenance Technology April 2017 - 56
Maintenance Technology April 2017 - Cover3
Maintenance Technology April 2017 - Cover4
http://www.nxtbook.com/atp/MaintenanceTechnology/epfeb2020
http://www.nxtbook.com/atp/MaintenanceTechnology/epjan2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epnovdec2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epseptoct2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epmay2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epapril2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epmarch2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epfebruary2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epjanuary2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epdecember2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epnovember2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epoctober2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epseptember2019
http://www.nxtbook.com/atp/MaintenanceTechnology/epaugust2018
http://www.nxtbook.com/atp/MaintenanceTechnology/0818schneider
http://www.nxtbook.com/atp/MaintenanceTechnology/epjuly2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epjune2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epmay2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epapril2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epmarch2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epfebruary2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epjanuary2018
http://www.nxtbook.com/atp/MaintenanceTechnology/epdecember2017
http://www.nxtbook.com/atp/MaintenanceTechnology/epnovember2017
http://www.nxtbook.com/atp/MaintenanceTechnology/epoctober2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtsept2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtaugust2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtjuly2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtjune2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtmay2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtapril2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtmarch2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtfebruary2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtjanuary2017
http://www.nxtbook.com/atp/MaintenanceTechnology/mtdecember2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtnovember2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtoctober2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtseptember2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtaugust2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtjuly2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtjune2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtmay2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtapril2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtmarch2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtfebruary2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtjanuary2016
http://www.nxtbook.com/atp/MaintenanceTechnology/mtdecember2015
http://www.nxtbook.com/atp/MaintenanceTechnology/mtnovember2015
http://www.nxtbook.com/atp/MaintenanceTechnology/mtoctober2015
http://www.nxtbook.com/atp/MaintenanceTechnology/mtseptember2015
http://www.nxtbook.com/atp/MaintenanceTechnology/MTAugust2015
http://www.nxtbook.com/atp/MaintenanceTechnology/MTJuly2015
http://www.nxtbook.com/atp/MaintenanceTechnology/MTJune2015
http://www.nxtbook.com/atp/MaintenanceTechnology/M
http://www.nxtbook.com/atp/MaintenanceTechnology/0415endress
http://www.nxtbook.com/atp/MaintenanceTechnology/MTApril2015
http://www.nxtbook.com/atp/MaintenanceTechnology/MTMarch2015
http://www.nxtbook.com/atp/MaintenanceTechnology/MTFebruary2015
http://www.nxtbook.com/atp/MaintenanceTechnology/MTJanuary2015
http://www.nxtbook.com/atp/MaintenanceTechnology/MTDecember2014
http://www.nxtbook.com/atp/MaintenanceTechnology/MTNovember2014
http://www.nxtbook.com/atp/MaintenanceTechnology/MTOctober2014
http://www.nxtbook.com/atp/MaintenanceTechnology/MTSeptember2014
http://www.nxtbook.com/atp/MaintenanceTechnology/MTAugust2014
http://www.nxtbook.com/atp/MaintenanceTechnology/MTJuly2014
http://www.nxtbookMEDIA.com