May 1, 2003
You'd like to think your customers install the products they buy from you in electrical systems that meet all requirement of the National Electrical Code

You'd like to think your customers install the products they buy from you in electrical systems that meet all requirement of the National Electrical Code (NEC). Unfortunately, it doesn't always happen that way.

In this article, Electrical Wholesaling's editors picked a few of the dozens of Code conundrums that have run in Joe Tedesco's columns in EC&M and CEE News (until it was merged into EC&M in September 2002). Some of these NEC violations would be funny if they weren't so dangerous. We have all heard the horrific stories of what happens when some numbskull isn't paying attention or is trying to cut corners on the job.

Tedesco has spent much of his career as an electrical inspector in Massachusetts and California. A noted author and teacher, Tedesco travels the United States doing seminars for electricians and electrical inspectors on proper compliance with the NEC.

Joe has also made a name for himself shining a light on the worst examples of non-NEC compliance and poor electrical workmanship. He does this in articles in EC&M and on his Web site at www.joetedesco.com. Many of the Code violations are those he discovers in his travels; others are sent to him by electrical inspectors and other electrical professionals.

If you or your customers spot an NEC violation, take a photo and send a brief background statement describing the error and your interpretation of how it violates the NEC to Joe at [email protected]. Your submissions could be published on Joe's Web site and in EC&M magazine.

Really scary

One of my former students who was a home inspector sent this photo to me. He found this “homemade extension cord” in a client's garage. The homeowner said he used it to save batteries so he could use the adapter to power up his portable television while floating around in his pool.

(Editor's note: This NEC violation is regarded by the editorial staffs of Primedia's electrical publications as the worst of the worst. If there was an NEC “Hall of Shame” award, it would be a leading candidate).

Jungle law snakes through live busbars

This incredible photograph came from a master electrician named Hannes van Wyk. He has a certificate in Hamburg, Germany, and in South Africa. He runs a contracting business called Cable and Connect Electrical. The picture shows what must have been quite a dramatic struggle for life that took place in Cape Town, South Africa.

This electrical equipment contained live busbars that were enclosed. The snake chased a mouse through a rigid metal conduit leading into this enclosure from a nearby panelboard. Both were killed (fried to a crisp, actually) between the phases at over 400V between the busbars. A snake specialist identified the snake as one of the world's most poisonous snakes, namely a Cape Cobra. Fortunately, it did not happen on one of Hannes' installations.

Don't make light of this lampholder

The lampholder in this recessed incandescent lighting fixture was discovered under a mini shopping mall overhang in Minneapolis. The extension cord was plugged into a screw-shell adapter that was used to supply another adapter. It energized a string of decorative lighting that was secured to the entire perimeter of the overhang. This violates Section 410.47. Lampholders of the screw-shell type shall be installed for use as lampholders only.

Conduit mowed over

A lawnmower damaged a conduit at the base of a parking lot light near the entrance to a restaurant. I discovered this circuit was still energized later that day. I am always amazed when I find this situation around these types of installations. If the conduit here was anything other than nonmetallic, this situation may have only caused damage to the lawnmower blade. The rules in the NEC under Section 300.5(d) cover protection from damage. Direct buried conductors and cables emerging from the ground must be protected by enclosures or raceways extending from the minimum cover distance required by Section 300.5(a) below grade to a point at least 8 feet above finished grade. In no case shall the protection be required to exceed 18 inches below finished grade. Where the enclosure or raceway is subject to “physical damage,” the conductors must be installed in “rigid metal conduit, intermediate metal conduit, Schedule 80 rigid nonmetallic conduit” or an equivalent.

One slice please

This brand new pizza oven was installed at a well-known pizza chain in a major airport. The disconnecting means for these ovens is not readily accessible under any circumstances. The clearances for 6-1/2 feet of height from the floor in front of this disconnect may be met, but the access to the required working space is nonexistent. Section 110.26(a)(1) requires that the depth of the working space in the direction of access to live parts cannot be less than indicated in Table 110.26(a). Distances are measured from the live parts if exposed, or from the enclosure front or opening, if enclosed. Section 110.26(a)(2) says work space must permit at least a 90-degree opening of doors or hinged panels.

Look Ma, No fitting!

This is a surface metal raceway wiring method permitted by Article 386. It's often used when adding circuits in an existing building where it would be difficult to fish cables through the wall or ceilings of concrete. This is one of the easiest ways to accomplish the run to supply equipment. In this case the circuit was three-phase, 208V with an equipment-grounding conductor. The fitting, which would ensure that the raceway was connected properly, was missing.

Section 386.21 covers the size of conductors, indicating that no conductor larger than that for which the raceway is designedcan be installed in surface metal raceway. Section 386.22 covers the number of conductors or cables allowed to be installed in surface metal raceway. This rule says the numbercannot be greater than the number for which the raceway is designed.

No sign of an exit here

This commercial building exit light was not in working order and not properly connected. It had exposed live splices, a lost equipment grounding conductor and was also hidden from view because of a foreign system that was run right in front of the word, “exit.”

I seem to find this type of hazard during my travels when I look for exits from a building, just after arriving. You can take your pick of violations here, and just open the Code book starting in Article 110 and go 10 pages forward, or 10 pages backward and most likely will find a rule to cite.

Better yet, call the fire marshal, building, mechanical, and plumbing inspectors and ask them for a rule that can be cited in their codes, documents or local rules. I am sure the rules would be available to be added to your list. My question: who would allow this to remain? I have got to say again, political interference is probably one reason.

Troubled splices

A qualified electrician and installer, Bob Naranjo, sent this picture. Naranjo went on a routine troubleshooting call to a commercial building because the property management office wanted to know why their security gate system circuit breakers kept tripping. The original installers failed to use proper splicing methods and materials in a wet location. After a few days of corrections and repairs, and compliance with Section 110.14, the situation is now under control. This NEC section requires that devices such as pressure-terminal or pressure-splicing connectors and soldering lugs shall be identified for the material of the conductor and must be properly installed and used. Conductors of dissimilar metals cannot be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use.

Don't fence me in

The meter socket enclosure and other equipment were not going to come between a homeowner's new brick wall and wrought-iron fence and the existing property line.

The overcurrent devices may have been considered to bereadily accessible after removal of the fence bar, but this equipment with a permanent fence installed in front of it makes it a clear violation of the rules in 110.26.

Although I could not find any specific reference in Article 312 for working spaces, Article 408 may have an applicable rule. All that is really needed is the definition of “equipment” in Article 100. Equipmentis ageneral term including material, fittings, devices, appliances, luminaires (fixtures), apparatus and the like used as a part of, or in connection with, an electrical installation.

Improperly wired cord cap

Richard Graves, a licensed master electrician since 1986, was called out to look into a problem with a heat lamp circuit that was a part of a commercial food-warming table in a pizza parlor. The customer said every time the heat lamp cord was plugged into the wall receptacle, fire would “shoot out of the receptacle” and the circuit breaker would trip. When Graves checked the receptacle, he saw that although it was wired correctly, it was fried like a sausage. Richard replaced the cooked receptacle and removed the cord cap that was attached to the Type SO cord coming from the food warmer table/heat lamps. This was the first time he ever saw a cord cap wired in such a manner.

Boring shallow studs

Residential conduit installation requires some special consideration when there's a possibility that screws or nails can cause penetration.

When a raceway of this type (FMC)is installed where it's exposed or concealed and is run through bored holes in joists, rafters or wood members, the holes must be bored so that the edge of the hole is not less than 1-1/4 inch from the nearest edge of the wood member. In this case since a 2 inches × 3 inches wooden stud was used in this shed, compliance with Section300.4(a)(1) is not possible. A 1/16-inch-thick steel plate, or bushing, is required to be installed on both sides of this stud to protect the flexible metal conduit.

Be sure to check for the “appropriate length and width” of this protection. Also, see Section 300.4(a)(1), Exception, where this protection would not be required when rigid metal conduit (RMC), intermediate metal conduit (IMC), rigid nonmetallic conduit (RNMC) or electrical metallic tubing “thinwall” (EMT)was used in this manner.

Butchered terminals

Ken Smith, a maintenance and operations manager from the Kennewick, Wash., school district, sent this photograph of a serious violation discovered in one of the high schools — a damaged 350A rated, three-pole circuit breaker. To the best of Ken's knowledge, it was the original equipment installed when the school was built in 1970. This circuit breaker had been modified to accept 750MCM aluminum conductors. You can see where the support between the 500MCM and 250MCM connections was removed in order to get the 750MCM aluminum conductors to fit. When this circuit breaker was installed, the wires were cut back and lugs were crimped on the wire ends inserted into the sockets.

See Section 110.12(c) in the 1999 NEC. It states there can be no damaged internal parts of electrical equipment, including busbars, wiring terminals, insulators and other surfaces, that may adversely affect the safe operation or mechanical strength of the equipment. This includes parts that are broken, bent, cut, or deteriorated by corrosion, chemical action or overheating. It was fortunate that lives were not lost because of this terrible installation. This illegal equipment alteration also violates Section 90.7, for examination of equipment for safety.

Not enough wire

Can you count the number of circuits crammed in this raceway? This installation is located in a prestigious Massachusetts law school. The photo shows “four extension rings” that seem to have corrected the “improper cubic inch capacity” in the first box. However, because the conductors don't all extend 3 inches outside the opening from the final edge of the last extension ring, this installation violates the requirements of the National Electrical Code. (See Section 300.14.) Where the opening to an outlet, junction, or switch pointy is less than 8 inches in any dimension, the Code requires each conductor to be long enough to extend 3 inches outside of the opening.


Joe Tedesco is a certified electrical code instructor, and license law instructor for Massachusetts. He has been an electrical inspector in California, Massachusetts and Connecticut, and he is a licensed journeyman and master electrician in Massachusetts and a certified electrical inspector and electrical-plans examiner for the International Association of Electrical Inspectors (IAEI), Richardson, Texas.

Along with being an NEC consultant, he is also program manager, National Technology Transfer Inc., Englewood, Colo., and develops and presents seminars on the NEC, grounding, and electrical inspection nationwide. The author of several books on the NEC Joe has also written dozens of articles on the NEC and NEC violations for EC&M magazine, CEE News magazine and the International Association of Electrical Inspectors (IAEI).