The answer to this question appears at the end of this newsletter.


Summer Repairs
Summer affects your repair environment. Consider these examples:

• Hot parts brought into an air-conditioned space may be damaged by condensation. If that problem isn't accounted for, you may end up installing a new part that already needs to be replaced.
• Repairs take longer. Unlike heat stroke, heat fatigue isn't recognized as a health concern. Nevertheless, it is a productivity concern. During extreme weather, people tend to make more mistakes and/or work at a slower pace. If you need a 90-minute repair window under normal conditions, you might need two or three hours in extreme weather. Assess conditions, and adjust accordingly.
• A blackout shut down much of the Eastern Seaboard in the summer of 2005. Packages slated for overnight delivery sat idle for days. If you're planning a shutdown for repair and replacement, the Just-In-Time (JIT) method may prove to be the "just-too-late" method. Order parts with enough lead time to allow for contingencies. Don't forget that summer storms can also wreak havoc with airlines, delaying the arrival of key personnel.

Can you think of other repair complications that arise in summer? Have your team make a list, update it as new concerns develop, and focus on solving the top three problems each week.


Operation
NEC at the Facility
The one factor that is constant in facilities is that things will change. Keep this in mind when planning power distribution panel layouts. A panelboard is limited to a maximum of 42 overcurrent protection devices [408.35] (not including the mains). Allow room for additional breakers in a given panel, and allow space for an additional panel or two on a given wall.


Summer Safety Glasses
Eye protection violations seem to be more common in the summer. Partly, it's because people prefer the styling of their sunglasses to that of their safety glasses. Visibility is also a factor: A lens scratch can create a glare effect that you don't get with sunglasses.

In addition, people are increasingly aware of eye cancer risk and want the protection provided by UV-rated sunglasses. It's also true that many safety glasses aren't ergonomic and may feel uncomfortable.

Fortunately, there are many choices in safety glasses to solve these problems. The days of clunky black frames with clear flat lenses are gone. Safety glasses are available that look better than many sunglasses and offer superior UV protection and comfort.


Show & Events
Let's Go Racing! Win a Free Road America Race Weekend For Two.
EC&M magazine and Generac Power Systems have teamed up to offer an expenses-paid weekend (August 10-12, 2007) featuring two of the world's fastest racing series. The third annual Generac Power Weekend is one thrilling day of American LeMans series racing (the Generac 500) and an equally exciting day of Champ Car racing at its finest (the Generac Grand Prix). It's your chance to see both series compete in a single weekend at one of North America's most beautiful tracks. Located in the hilly heart of Wisconsin's scenic Kettle Moraine area, Road America is a four-mile permanent road course that tests drivers with 14 challenging turns.

Enter by July 10, 2007. Visit the Generac Power Systems virtual booth at the EC&M E-Tradeshow. Full contest rules are available online in the Generac E-Tradeshow booth. For more information about the Generac Power Weekend, go to www.roadamerica.com.



EC&M Code Change Conferences
Where do you turn when you need accurate information on changes to the National Electrical Code? Acknowledged as the leaders in providing information on the NEC, EC&M magazine and EC&M Seminars have been the preferred sources of this information for more than 60 years. Seven Code change conferences have been scheduled in the fall of 2007. Host cities include: Atlanta, Boston, Dallas, Orlando, Philadelphia, St. Louis, and Seattle.

As an approved provider with the National Council of Examiners for Engineering and Surveying (NCEES), through its Registered Continuing Education provider Program (RCEPP), professional engineers attending any of our 2008 Code change conferences will receive Professional Development Hours (PDHs), a requirement for re-licensing in many states. The conferences are also approved by every state that has a continuing education requirement for contractors and electricians.

For additional information on the dates and locations of these events, click here.


Quiz Answer
Answer to Electrical Troubleshooting Quiz
The nuisance tripping started in the spring -- when ceiling temperatures began to rise. That's a good clue.

As temperature rises, ampacity drops. This why you have temperature adjustment factors [310.10] and why voltage drop calculations factor in temperature and conductor size.

A portion of the feeder probably runs through a ceiling cavity that traps heat due to insufficient airflow or is just hot to begin with. Sizing that portion of the feeder for the correct ampacity will solve the voltage drop that is causing increased current demand.

Read through NEC Annex D, Example D3(a) to understand the solution to this problem.

IR readings can quickly reveal if you have an "Example D3(a) situation." If you don't, you've easily ruled out a likely cause. Your next step would be to start standard motor troubleshooting (begin with motor inputs).