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Nightmare Installations
Everything Including the Kitchen Sink
A tenant in a duplex called to say she felt a light tingling when she touched her kitchen sink. She also noticed a sparking and crackling around the light switch above the counter. The kitchen wall was done in copper tile from the counter top to the bottom of the upper cupboards. I figured there was some connection between one of the counter outlets and the copper tiles, but after looking at them I found nothing touching. I measured voltage from the wall to ground, so I turned off one breaker at a time while checking voltage at this point. The range breaker controlled the voltage. As it turned out, the landlord had recently installed a new range receptacle and put a hot wire onto the ground lug, thereby energizing the frame of the range, which in turn touched the copper tiles and energized the whole wall. No breakers ever tripped and no one was electrocuted.
Name and location withheld

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Night of the Living Appliances
When I first started doing service work, I received a very strange call from a customer who reported that when she turned on her stovetop, the dishwasher on the other side of the room would turn on as well. Both items were brand new, and the appliance service man couldn't figure it out. We started at the cord that fed the electronic igniter-type stove, and proceeded to take the whole unit apart as we traced the power wires coming in. Under the top of the burner area cover, we found that the neutral and hot had been reversed on the molded plug/connector at the factory. After we re-pinned the two wires properly, the problem was resolved. The hot wire that backfed through the neutral was somehow starting the electronic dishwasher on the other side of the kitchen. We thought she was nuts until we saw it happen with our own eyes!
Doug Blackburn
Yucaipa, 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
Properly applying the requirements of Code rules associated with overcurrent protective devices has always been a little tricky. To help Code users better understand the intent of the Code, several changes within Art. 240 (Overcurrent Protection) were accepted with the printing of the 2002 NEC. One of those changes relates to the protection of transformer secondary conductors (240.21).

A new subsection, 240.21(C)(6), provides language for secondary conductors longer than 10 feet, but not more than 25 feet. This rule was missing in the previous editions of the NEC. The 1999 Code contained the requirement for secondary conductors up to 25 feet for industrial installations only [240-21(c)(3)].

The secondary conductor must be sized no smaller than one-third the ampacity of the primary protection device based on the secondary/primary ratio. For all practical purposes this can be ignored, because typically the secondary conductors only supply one load. However, if the secondary conductors are to supply multiple loads, then the conductors must be sized to the 1/3 rule as follows:

Step 1: Primary current rating.
I = VA ÷ (E × 1.732)
I = 45,000 ÷ (480 × 1.732) = 54A

Step 2: Primary overcurrent protection device rating [450.3(B)].
Primary protection = 54A × 1.25 = 68A
Next size up permitted = 70A [240.3(B) and Table 450.3(B), Note 1]

Step 3: Minimum secondary conductor ampacity.
Secondary ampacity = primary protection rating × (primary voltage ÷ secondary voltage × 0.333)
Secondary ampacity = 70A × (480 ÷ 208 × 0.333) = 70A × 0.77 = 54A

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Code Challenge

What's Wrong Here?
By Joe Tedesco
How does this installation violate NEC requirements?

Hint: Does this look like a weather-proof installation to you?

Code Q&A
By Mike Holt
Q. When can hospital-grade MC cable of the interlocked type be used in a doctor or dentist examining room?
See the answer.

Code Quiz
By Steven Owen
Q. Two 480V motor control centers (MCCs) are located directly across the aisle from one another and face each other in an electrical distribution room. They're exactly 48 inches apart, which complies with Table 110.26(A)(1) for a Condition 3 spacing requirement. One of the existing MCCs is set to be replaced with a new MCC that's 5 inches deeper, but the existing MCC is set against a wall, so the new MCC will have to be installed in the exact location. This will cause the new MCC to extend 5 inches into the required working space between the two units. The proposed installation will allow 43 inches between them (front-to-front). What is the minimum spacing required for this proposed installation to be Code compliant?

48 inches

43 inches

42 inches

36 inches

Visit EC&M's Web site for the answer and explanation.

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Faces of the Code
Tug Miller
Member, Code-Making Panel 19
Given Tug Miller's love for the road, it seems fitting that his life's travels have taken him from the banks of the Hudson River across country to the West Coast. The son of an upstate New York dairy farmer, he decided in the early '70s to turn his travel and outdoor hobbies into a career, so he packed up his family and moved to Auburn, Calif., to build a Kampgrounds of America (KOA) campground. "It was a good time to do it," Miller says. "I had a family, we were campers, and we loved the industry."

It wasn't all s'mores and sing-alongs, though. Hoping to gain a voice in campground regulatory issues, Miller soon became the president of the California KOA owners' association and joined the California Travel Park Association (CTPA), of which he's now the co-executive director. And that ultimately led to his involvement with the National Association of RV Parks & Campgrounds, which he represents on CMP-19. "I became involved in the associations because I realized we needed a voice to be heard in Sacramento -- both at the regulatory level and at the legislative level," he says.

Foremost among his concerns -- and those of the associations he represents -- is making sure campers have safe accommodations at their outdoor homes away from home, and that includes placing requirements on RV manufacturers to specify electrical hook-ups in a place on their vehicles that's electrically safe. "That's one of the reasons I got involved in standards work," Miller says. "Manufacturers were putting water, sewer, and electricity hook-ups on the wrong side of RVs for the way most parks and campsites were built."

Miller has long since sold the campground he built when he first moved to California, but his love for the RV and camping industries is still strong. He took a few cycles off from CMP-19 during the '90s when his workload became too heavy, but he was glad to return for the 2005 cycle. "It was nice seeing some old faces," he says. "I plan on sticking around for a while."

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Speak Out
On the Road With the Code
For the most part, the Code is considered an installation standard for buildings and facilities. However, Art. 551 covers recreational vehicles. Should the Code place restrictions on motor vehicles -- even those that can double as living spaces? Now that so many people conduct business out of their cars and trucks, should those be covered as well in a separate Article? Visit EC&M's Web site to let us know. And feel free to e-mail us with your comments on the subject so we can share your thoughts with your fellow readers.

It doesn't get any closer than this. The issue of cutting the "uses permitted" section from the Articles covered by CMP-7 split you right down the middle, which leads us to believe we haven't heard the last of this topic.

We also asked you to give us your opinions on how to fix the problem of shoddy electrical installations. Your responses blamed everything from lack of training to big box DIY retailers for the decline of quality installations. Visit the Web site to see some of our favorite responses.

Shows and Events
EC&M 2005 Code Change Conferences
It's that time again. The release of the 2005 NEC is only months away, and to help you prepare for all of the changes, EC&M is once again presenting its Code Change Conferences. Moderated by Mike Holt and Fred Hartwell (Boston conference only), two of the electrical construction industry's most knowledgeable trainers, the two-day conferences will cover everything you need to know about the new Code. All attendees will receive a copy of the 2005 NEC and EC&M's 2005 Code Change Book, written by Mike Holt. Seven seminars will be held in various cities across the country. Download the registration form to find the closest seminar, fill it out, and fax it to (203) 929-5351.

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