| CONTENTS
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Fire
House Fire Trap
If You Can't
Stand the Heat...
Code Basics
What's
Wrong
Here?
Code Q&A
Code Quiz
Faces
of the Code
Wireless
Wonders
EC&M Code Conferences
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About this Newsletter
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Nightmare Installations
Fire House Fire
Trap
As an electrical instructor for an adult evening
school,
I get asked by many of my students for field advice. One of the more
alarming installations I was called out to investigate was in a local
fire/emergency squad building. Someone in this unit had made repairs to
an old Pushmatic panel, where the main circuit breaker had failed and
burned. This "qualified" individual's fix consisted of drilling two
holes in the blackened panel and bolting on a new circuit breaker and
back-feeding the burnt and blackened panel. The use of standard bolts
and poor connections to the bus bar again led to an overheating
situation. When asked for my recommendation on adding some new circuits
to this panel I gave this reply: Hire a real electrical contractor to
replace this mess or you'll be calling yourselves shortly.
Robert J. Sheridan
Marlton, N.J.
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If You Can't Stand the
Heat...
During the remodeling of the kitchen in our home,
demolition of the false ceiling revealed water pipes sloppily run under
the main floor joists and Romex lying on top of the hot and cold water
pipes. The Romex fed the kitchen and upstairs bedroom loads. This
installation saved the homebuilder or the electrician some expense, as
the electrician didn't have to drill holes in the floor joists or use
any kind of approved attachment method to properly support the
conductors. The real surprise came when the plumber went to remove and
reroute the hot and cold water pipes. The outer covering of the Romex
in
contact with the hot water pipe had melted, as well as a portion of the
outer insulation of the conductors. Fortunately, I know of only one
"electrical" fire that has occurred in the neighborhood because of this
situation.
Bob Wilson
Dana Point, Calif.
Send your 200-word story to us and it may
appear in a future issue of CodeWatch. Authors of stories chosen for
publication will receive $25.
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Applications Corner
Code Basics
By Mike Holt
The NEC requires you to ground (earth) system windings
to limit the voltage imposed on the system from lightning,
unintentional
contact with higher-voltage lines, or line surges. When lightning
occurs, high voltages drive high current (as much as 40,000A) into the
earth for a fraction of a second. Typically, lightning strikes to
wiring
are directed to outside utility wiring systems. Therefore, grounding
(earthing) the
system windings will assist the flow of lightning into the earth.
When a ground fault over 600V occurs, the voltage on the other
phases
can rise significantly for the duration of the fault (typically three to
12
cycles). This voltage surge during the utility ground fault will be
transformed into an elevated surge voltage on the secondary -- possibly
destroying electrical and electronic equipment. The lower the
resistance
of the utility grounding (earthing) system, the lower the secondary
voltage surge.
Another function of this earthing is to "stabilize the voltage to
earth during normal operation" by providing a common reference point.
Thus, the NEC also requires you to ground (earth) metal parts of
electrical equipment in or on a building or structure. See 250.24(A)
for
services and 250.32(A) for separate buildings or structures. You
accomplish this grounding (earthing) by electrically connecting the
building or structure disconnecting means (225.31 or 230.70) -- with a
grounding (earthing) electrode conductor [250.64(A)] -- to a grounding
(earthing) electrode [250.52, 250.24(A) and 250.32(A)].
However, grounding (earthing) the metal parts of electrical
equipment
doesn't protect this equipment from lightning-induced voltage
transients
or those generated by other equipment in the structure. To provide
protection from voltage surges, you must engineer a proper surge
protection system.
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Code Challenge
What's Wrong Here?
By Joe Tedesco
How does this
installation violate NEC requirements?
Hint: The conduit and other raceway at the Park Street MBTA
station in Boston is separated where passing through the sleeve to the
station below.
Code Q&A
By Mike Holt
Q. When does the NEC require a main breaker in a
load center?
See the answer.
Code Quiz
By Steven Owen
According to the 2005 NEC, ground-fault
circuit-interrupter protection for 125V, 15A or 20A receptacles is
required for which of the following locations?
- near a commercial boathouse, without access to the
public
- in a crawl space of an industrial building
- on the 2nd floor of a dwelling unit garage that provides no access
to vehicles
- outdoors in a public park where accessible to the general
public
Visit EC&M's Web
site
for the answer and explanation.
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Faces of the Code
Roland
Gubisch Member, Code-Making Panel 16
It's been 34 years since Roland Gubisch returned to the
United States as a freshly minted doctoral graduate of the University
of
Cambridge, but his experiences overseas still have an affect on his
life
and approach to work. He didn't know it at the time -- in fact, he
didn't even realize it until prompted to look back at his career -- but
the three years he spent in England would be instrumental in his
current
job at Intertek Testing Services. "Living over there opened me up to
alternate
ways of doing things," he says. "That kind of mindset is very helpful
with what I do, which is very broadly based in a discipline where
regulations and regulatory procedures are changing all the time."
Keeping up with those changes is a critical concern. As the chief
engineer for electromagnetic compatibility and telecommunications,
Gubisch is expected to provide engineering support for the testing
laboratory's North American locations as well as communicate domestic
testing requirements to its laboratories in Europe and the Far East.
"The differences between one country's requirements and another's
aren't
typically very large, but even small ones can be a real problem if the
manufacturer isn't aware of them," he says. "So paying attention to
detail is very important."
After working in the fields of medical instrumentation and
instrumentation in general, Gubisch began to specialize in
communications cabling -- he holds patents for measuring their
characteristics -- and eventually settled on EMC and telecommunications
at Intertek, which is ironic, given that some of the most common
devices
he now tests are WiFi routers for wireless communications among
laptops.
That increasing specialization in communications cabling made him a
natural candidate to represent Intertek on Code-Making Panel 16, which
covers Art. 800, 810, 820, and 830, when a slot opened up during the
2002 Code cycle.
He works with codes and standards everyday, but being a part of a
team that develops them was a new experience, and one that required a
lot of learning in a short amount of time. He's quick to credit his
fellow panel members for helping in the transition and making it an
enjoyable one. "You have a great breadth of experience as well as types
of experience to draw upon," he says. "It's rewarding to bring all of
those viewpoints together in one narrow area."
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Speak Out
Wireless Wonders
Roland Gubisch is testing a lot of wireless routers and
cards these days in response to the growing number of wireless networks
being installed across the country. Has the WiFi network craze had any
effect on your business? Visit www.ecmweb.com to share your thoughts.
It seems that a little premature exposure to the Code may not be
such
a bad thing. A little more than one-third (37%) of CodeWatch readers
noted they had been exposed to the Code prior to taking their first job
in the industry. Maybe the industry should create a Code 101 course and
try to push it out to the nation's high schools in an attempt to head
off the proposed labor shortage.
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The National Electrical Code Internet Connection, the No. 1
rated Code Web site in the world, offers the following FREE products:
Books, Code Quiz, DVDs, Graphics for PowerPoint, Newsletter, Online
Training, Posters, Simulated Exams, Software, Video clips, and Videos
Visit www.NECcode.com and stay
current with important industry issues.
Shows and Events
EC&M Code
Conferences
After some serious negotiating and good old
arm-twisting, we've convinced our conference manager to give us one
final extension on the registration deadlines for each of these
training
sessions. The new deadline for the Atlanta conference is Oct. 26th.
The new deadline for the Philadelphia, Chicago, and Orlando
Code Change conferences is Oct. 30th. The new deadline for the Boston
conference is Nov. 19th. And the new deadline for the
San Francisco and Seattle conferences is Nov. 24th. Download
the registration form, fill it out and fax it to (203) 929-5351 before
it's too late. Moderated by Mike Holt and Fred Hartwell (Boston
conference only), the two-day conferences will offer a comprehensive
look at the 2005 Code. All attendees will receive a copy of the 2005
NEC
and EC&M's 2005 Code Change Book, written by Mike Holt.
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