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TEGG SERVICES
Ultrasound Testing
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Spectrum Analysis Wave
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Arcing Spectrum
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Knights' Electric's TEGG Services
uses the most technologically advanced diagnostic tools on the market today. We are often asked, "At what voltages and on what type of equipment is ultrasound testing most effective?" The majority of electric problems detected with ultrasound testing are partial discharge, arcing, tracking and corona.
Ultrasound detects the ionization of air as it produces turbulence. This can be from corona, tracking or arcing. Heat is produced when there is either resistance due to
corrosion or from tracking and arcing. Since heat is produced by the flow of current through corrosion or resistance, you can have a "hot spot" detectable with IR (Infrared Imaging),
and have no ultrasound because there is no ionization. |
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 When arcing occurs, it is often accompanied by heat. However, it is not always possible to detect a hot spot if the equipment is covered.
Ultrasound will hear arcing in circuit breakers, switches, contacts and relays. In most instances, a quick scan of a door seal or vent will detect the ultrasound emission.
Listening for internal arcing in circuit breakers and switches can be accomplished with the contact probe. For example, touch a circuit breaker switch with the contact probe to listen
for internally generated arcing. The most effective method of low voltage inspection will be to combine infrared imaging with an ultrasonic probe.
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Higher voltages often produce more potential for equipment outage. Problems such as arcing, destructive corona
or tracking (sometimes referred to as "baby arcing") and corona as well as partial discharges and mechanical looseness all produce detectable ultrasound, that warn of
impending failure. Detecting these emissions is relatively easy with ultrasound. The acoustic difference among these potentially destructive events is the sound pattern. Arcing
produces erratic bursts, with sudden starts and stops of energy, while corona is a steady "buzzing" sound. Destructive corona has a build up and drop-off of energy
resulting in a buzzing sound accompanied by subtle popping noises. Partial discharge (PD), which occurs inside electrical components such as in transformers and insulated buss bars,
is another problem that can be detected with ultrasound. Partial discharge can be quite destructive. It is effected by and causes deterioration of insulation. This is heard as a
combination of buzzing and popping noises. While it is relatively easy to determine arcing, tracking or corona by the sound pattern, there can be occasions where it may prove
confusing. It may be possible that a strong buzzing sound related to corona might in fact be nothing more than mechanical looseness. Spectral analysis can be a useful tool in
analyzing electric emissions. These sounds can then be downloaded to a PC. As the condition becomes more severe, there will be fewer and fewer 60 Hz harmonics observed. As an
example, arcing has very few 60-cycle components. Mechanical looseness will be "rich" in 60 Hz harmonics and will have little frequency content between the 60 Hz peaks and will also
demonstrate harmonics other than 60 Hz. Ultrasound testing is an integral part of Knights' Electric's TEGG Service procedures for uncovering potential electrical problems and
failures. Ultrasound testing is also a key safety factor in the electrical testing procedures used by Knights' Electric's TEGG Services, a subject that we will cover next month. |
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COMMERCIAL
Art Knight – Changing With The Times
After twenty years in the business Art Knight is not reflecting back as much as he is projecting forward to meet
the upcoming challenges in commercial construction. "I started in this business right out of high school and spent 13 years in the field and then became an estimator under my dad (Bob
Knight) seven years ago," says Knight, who along with his brother Rob Knight maintains the title of Vice President of Knights' Electric, Inc. |
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Art Knight, V.P. and Commercial Manager of Knights' Electric, Inc., is in his
20th year with the company. |
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Art Knight, as chief estimator, oversees the bidding process that he, Richard Freitas and Ben English handle in the commercial department. "Richard has been here for over a year and has also taken on a good portion of the
estimating and project management work. He has a knack for getting through the paper work so we have been doing more municipal projects
– I believe that's an area we could expand in the future." Ben English has extensive experience in all commercial areas for Knights' Electric and has been estimating for over three years. "We all brainstorm together on some of the bigger and more difficult projects," says Knight.
"Everything has changed over the past few years," says Knight, "We used to bid jobs the old-fashioned way by taking off the job by hand and having the office price out all of the
material which was very time consuming, now we have a computerized estimating software program that has really made things easier and more accurate. Our bidding software is tied into
the pricing software in the office so we can come up with an estimate quickly." Some things haven't changed in the business over the years, like the relationships that
have been formed with customers, "My role is also to meet with old and new customers no matter what size project they are wanting to do," says Knight.
When Knights' Electric is chosen to do or is bidding on a design/build project, as many of the winery and commercial projects are,
Knight will be the one to put together the pricing, negotiate and manage the project, "Design/build projects are one of our real strengths," says Knight "that's another area of work
we want to expand in the future."Now Knights' Electric has TEGG Services
, which is broadening the customer base for commercial work. Along with more municipal work and negotiated design/build
projects the commercial department at Knights' Electric is changing and growing. |
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RESIDENTIAL
Using the Right Stuff
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Juno recessed lighting fixtures are a favorite choice of Knights' Electric and their customers.
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Knights' Electric's residential department specializes in custom home construction along with custom remodeling
and retrofitting projects. Many of the upscale custom homes have electrical lighting systems with Lutron HomeWorks
lighting control systems. Many contractors, architects, designers and homeowners consider Lutron products top of the line.Matt Sweeney, Residential Project Manager at Knights' Electric, uses Lutron almost exclusively when the application calls for a sophisticated lighting
control system. So, aside from Lutron, what are some of the other electrical products that Knights' Electric uses and recommends to its customers? |
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The Leviton Structured Media Center brings
the home's technology distribution all together
in one place.
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Sweeney points out that Knights' Electric always uses the best possible lighting brands for all of the lighting
systems they install. "We like to use Juno
recessed lighting fixtures and we recommend Juno to our customers". Juno supplies recessed lighting fixtures for residential and commercial applications in a wide variety of directional lighting fixtures. Their products include commercial incandescent, compact fluorescent, linear fluorescent, high intensity discharge (HID) and more.
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Knights' Electric also uses high quality components in other aspects of constructions besides lighting, "For
bath exhaust fans we use Panasonic," says Sweeney, "The big selling point for Panasonic is that
they are extremely quiet. Another brand might have a greater overall power capacity, but for high usage the quiet motor is most important to customers". |
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For cable and phone systems Knights' Electric likes to go with the Leviton Structured Media Center
, which comes in ready to go kits or empty enclosures to build a custom configuration. The Leviton Structured Media
Center has the capability to bring every conceivable technology distribution point together in one place. |
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This Panasonic bathroom exhaust fan,
combined with an overhead light here,
is popular because it is quite.
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Regardless of the type of lighting and electrical system Knights' Electric is installing it's important to know
that they always use the best possible product for the best possible results and customer satisfaction – Knights' Electric uses the right stuff. |
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