Cast Your Vote!
Electrical Troubleshooting Quiz
Tracing Power Events to Their Source
NEC at the Facility
The Practical Implications of OSHA 1926.406
Answer to Electrical Troubleshooting Quiz
About This Newsletter
e-newsletter is brought to you from the
publisher of EC&M magazine.
MRO Insider addresses topics such
Working with management and supervision
National Electrical Code® on the production floor
Safety procedures and programs
Equipment maintenance and testing tips
Managing motors and generators
Trends in training and education
Managing energy use
To unsubscribe from this newsletter go to: Unsubscribe|
To subscribe to this newsletter, go to: Subscribe
To get this newsletter in a different format (Text or HTML),
or to change your e-mail address, please visit your profile
page to change your delivery preferences.
issue? Visit the MRO
Insider archive page on the EC&M Web site.|
Share with a Friend
Do you know
someone who’d like to receive his or her own copy of MRO Insider? Visit
the subscriber site enter their e-mail address, and spread the wealth.
To find out
how to advertise in this newsletter, e-mail David Miller or call him at
The designations "National Electrical Code” and “NEC” refer to the
National Electrical Code®, which is a registered
trademark of the
National Fire Protection Association.
Product of the Year Competition
Cast Your Vote!
Do you want the opportunity to win $100? Then visit the
EC&M Web site by June 30 to
your vote in EC&M's Product of the Year competition and help us
to identify the best new product introduced for the electrical industry
When you visit the EC&M Product of the Year
page, an automatic poll will pop up. (Note: If you have a pop-up
blocker program, it may prevent you from seeing the poll. Temporarily
disable the program to allow the poll to appear on your computer.) You
then need to type in your contact information, choose your favorite
product, and click submit. It's that simple.
A panel of nine judges narrowed the field from 114 entrants to 24
category finalists, and now we need your help to determine the Platinum
Award winner. The competition has honored innovation and excellence in
product development in the electrical industry for the past six years.
touch panel is available in 6-, 8-, 10-, 12- or 15-inch versions.
Equipped with an analog touch screen that eliminates defined touch cell
boundaries, C-more's configuration software allows objects to be
scaled and overlapped without limitation. Advanced capabilities include
built-in e-mail client, FTP and web servers.
We all know that post hurricane Katrina rebuilding
efforts have pumped a lot of rebuilding dollars into the Gulf Coast
market, but don't forget about the traditional planned expenditures in
this area. There is currently more than $2.4 billion in greenfield
construction, expansion, and maintenance-related projects on tap in
Mississippi alone, according to marketing information resources company
Industrial Information Resources (IIR).
Mississippi is home to more
than 650 operational industrial plants.
Industrial-scale construction projects got off to a strong start this
year with site work at SeverCorr's $700 million steel mini-mill. The
plant is scheduled to come online in 2008. Construction kickoff on a
$140 million engineered wood manufacturing plant will push spending in
the pulp, paper and wood industry to $205 million. And IIR projects
expenditures of $577 million in capital and maintenance from 41
in the industrial manufacturing industry.
A power monitor is more than just a great forensics
tool. You get a huge return on investment if you use a power monitoring
system as a predictive maintenance tool. A well-thought-out monitoring
system, as opposed to a single-point-only monitor, looks at all of the
important power points in your facility.
The monitoring system can show trends, such as growing voltage
imbalances or increasing levels of harmonics. It's particularly useful
to set the monitor to alert you for specific events. Doing so can help
prevent unscheduled downtime. For example, have the system alert you
when there's been a voltage spike of X magnitude (X being determined
engineering review). A single such spike may not cause problems.
But suppose you get an X magnitude or larger spike every time
equipment starts. Over time, the cumulative conductor insulation damage
will cause failure. It's a fundamental law of electricity that the
failure will happen either the day before your vacation or just before
your performance review.
The monitor can make you aware of the spike and can track
recurrences. Armed with that information, you can determine the source.
Your next step is preventive repair.
For Quick Motor
Decontactors are a combination plug & receptacle and disconnect
switch. They allow electrical equipment to be safely and easily
disconnected and connected - up to 60 hp or 200A. Since there is no
access to live parts workers can change out a motor without having to
'suit-up'. Inquire about our free trial program.
Meltric Corporation, call 800-433-7642, www.Meltric.com
Reviewing your power monitoring logs for the past six
months, you notice an odd trend that coincided with an uptick in
equipment troubles. Voltage levels in some production areas are
significantly lower in the morning than in the afternoon. But
are identical during the two times, and there is no equipment start-up
-- nor is this a facility-wide issue. Even more interesting, the
problem seemed to clear up all on its own last month, after -- along
with the equipment trouble rate -- steadily improving over the
preceding two months. Yet, you've had no configuration changes.
How can you determine what this was, so you can stop it from coming
The answer to this question appears at the end of this
Tracing Power Events to Their
Nothing is more frustrating than seeing a problem but
being unable to do anything about it. For example, your power monitor
reveals a consistent pattern of high-energy power spikes. You are
looking forward to the Fourth of July, but you don't want to see
fireworks in June -- and you certainly don't want to generate them
a cable fault. How can you find the power event source so you can
Power quality experts use a methodical approach and standardized
techniques that, while logical and effective, are fairly elaborate. For
a thorough analysis and solution, you should apply those techniques.
However, event correlation (one technique from their repertoire) may
allow you to troubleshoot quickly.
With event correlation, you note when each power anomaly occurred.
Then, you compare the times to operations. You may find, for example,
there's a shift change coincidental with each anomaly.
But what if the anomalies occur seemingly at random? Things may not
be random, after all. Talk to individual operators, reviewing when each
anomaly occurred. Each anomaly may have coincided with some operational
procedure such as a batch change or random operation of a large scrap
Exclusive TightSight Display Helps Set a New
Standard for Clamp Meters.
They're packed with features and like nothing you've ever seen before.
When we began designing the line, we certainly started at the bottom
worked our way up. The innovative TightSight display
gives you a level of testing freedom and safety beyond any test tool on
the market. In tight, dark or bright locations, it's invaluable. Other
features like a high voltage indicator will ensure that you've never
felt safer. Visit www.idealindustries.com for a
preview of the 600A and 1000A clamp meters from IDEAL.
NEC at the Facility
Art. 250 is (arguably) the most commonly misapplied
Article of the NEC. A major reason for misapplication is the NEC's
confusing use of "grounding" to mean "bonding." In Art. 100, we see
"grounding" means "connected to the earth". But "bonding" involves
establishing a conductive path back to the source. NEC Figure 250.4
shows bonding (Part V) tied to six of the nine Parts of Article 250.
This has serious implications for any facility.
For example, suppose you are experiencing motor failure, and
post-mortem examination shows severe pitting in the bearings. This is
almost surely due to "grounding" used in place of bonding. If you drive
a ground rod next to the motor instead of bonding the "ground"
connection to the main bonding jumper, you have provided a
high-impedance path back to the source.
Electricity follows all paths before it. Current flows in inverse
proportion to the resistances of those paths. Without the correct
bonding, you create a preferred return path right through the motor
bearings. Consequently, your "grounding" results in pitted bearings and
premature motor failure. Providing a low-impedance path via bonding
dramatically reduce current flow through the bearings. To prove this,
draw out the circuit (with possible return paths) and apply Kirchoff's
The Practical Implications
This addresses safety issues for cranes, elevators,
escalators, welders, and x-ray machines. The goals are basically to
prevent personal contact with energized conductors and to prevent
accidental operation of the equipment.
At the core of achieving these goals is the disconnecting means.
closely at each disconnect in your facility. Is it readily
accessible? During the original installation, the definition of
"readily" might have been stretched. For example, a disconnect mounted
such that a person cannot stand to the right of it and operate it with
the left hand is not readily accessible. Other requirements also apply
to disconnects -- be sure your installation complies.
Replacement Contacts for Motor Starters &
Quality, low-cost electrical contacts for industrial motor starters &
contactors. Repco replacements for Allen-Bradley, ABB, Clark,
Cutler-Hammer, Furnas, GE, Hubbell, Siemens, Square D & Westinghouse.
Square D series available: Current & Obsolete Devices, Class 7004
Answer to Electrical
Notice the timing. This is now June. Six months ago,
were in the dead of winter. Things began to improve as the weather
warming. The problem "cleared up on its own" in May. So, this is
probably temperature-related. However, the low voltage is isolated to
specific areas in the facility.
Your next troubleshooting step is to ask individual production
if their work area was too cold in winter. If so, they probably were
using personal space heaters. A clue here is the morning versus
afternoon voltage levels. Personal space heater use tends to be heavier
in the mornings. If company policy forbids personal heaters, that
doesn't mean people weren't using them. Previous complaints about a
comfort problem may have fallen on deaf ears.
Try to solve the root problem by adjusting the make-up air. You may
need to repair or upgrade your existing HVAC controls to do this. Also,
examine your power distribution to ensure convenience receptacles don't
(eventually) share the production equipment feeder.
You are subscribed to this newsletter as #email#
For questions concerning delivery of this newsletter, please contact
Customer Service Department at:
Customer Service Department
A Prism Business Media publication
US Toll Free: 866-505-7173
Prism Business Media
9800 Metcalf Avenue
Overland Park, KS 66212
Copyright 2006, Prism Business Media. All rights reserved. This article
is protected by United States copyright and other intellectual property
laws and may not be reproduced, rewritten, distributed,
displayed, published or broadcast, directly or indirectly, in any
without the prior written permission of Prism Business Media.