Ecmweb 3167 212ec30pic1
Ecmweb 3167 212ec30pic1
Ecmweb 3167 212ec30pic1
Ecmweb 3167 212ec30pic1
Ecmweb 3167 212ec30pic1

Illustrated Catastrophes

Dec. 1, 2002
As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without criticizing anyone or any product, the following scenarios present us with serious electrical safety questions.

As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without criticizing anyone or any product, the following scenarios present us with serious electrical safety questions.

Rusty Wireway

A metal wireway is a sheet metal trough with a hinged or removable cover used for housing and protecting electric wires and cable. Typically, the conductors are laid in place after the wireway has been installed as a complete system (376.2). The Code doesn't permit you to locate wireways where they're subjected to severe physical damage or severe corrosive environments [376.12(1) and (2)].

This installation was discovered near Baltimore's Inner Harbor in a downtown parking structure. Almost all of the exposed wiring methods located on the ceiling at street level were found in this condition. The local environmental conditions probably caused the corrosion. All materials are required to be suitable for the environment in which they're to be installed. See 300.6 for rules concerning protection against corrosion.

Missing Bushing

Throughout Chapter 3 of the NEC, a Fine Print Note (FPN) calls attention to 300.4(F), Insulated Fittings. This rule requires the use of insulated fittings when raceways containing ungrounded conductors 4 AWG or larger enter a cabinet, box enclosure, or raceway. A substantial fitting providing a smoothly rounded insulating surface usually provides the protection for the conductors, unless the conductors are separated from the fitting or raceway by substantial insulating material that is securely fastened in place. Conduit bushings constructed wholly of insulating material can't be used to secure a fitting or raceway. The insulating fitting or material must have a temperature rating not less than the insulation temperature rating of the installed conductors. This cabinet violates that rule because the fitting at the bottom right is metal. As a side note, this cabinet was also being used as a storage bin for the spare circuit breakers located in the bottom of the cabinet.

Check Ribbon Installation

The NEC requires the location of underground service conductors not encased in concrete or buried 18 in. or more below grade to be identified with a warning ribbon placed in the trench at least 12 in. above the underground installation. [300.5(D)(3)]. Where the cables are energized at more than 600V, as in this installation, Table 300.50 notes the minimum cover requirements required by the Code.

Now you can send Illustrated Catastrophes stories and photos directly to Joe Tedesco at:

Joe Tedesco
350 North Street
Boston, MA 02113 or e-mail:
[email protected]

If you mail pictures, please include the story, location, and some information about yourself — and please do not write on the front or back of your photo. Please send all digital images in JPEG format. You can send photos while visiting Joe's Web site at www.joetedesco.com.

About the Author

Joe Tedesco

Tedesco served the industry in many roles during his career. He was a director, senior electrical code instructor for National Technology Transfer, Inc. and American Trainco, Inc.. He was also a codes, standards and seminar specialist for the International Association of Electrical Inspectors and an electrical field service specialist for the National Fire Protection Association in Quincy, Mass. He ran his own business as an NEC consultant and is a Massachusetts licensed master electrician and journeyman electrician and certified electrical inspector (one and two family 2A; General 2B, and Plan Review, 2C). Tedesco also wrote articles for CEE News and EC&M (Code Violations Illustrated and What's Wrong Here?) for more than 15 years and helped launched the Moving Violations video series.

Voice your opinion!

To join the conversation, and become an exclusive member of EC&M, create an account today!

Sponsored Recommendations

Electrical Conduit Comparison Chart

CHAMPION FIBERGLASS electrical conduit is a lightweight, durable option that provides lasting savings when compared to other materials. Compare electrical conduit types including...

Don't Let Burn-Through Threaten Another Data Center or Utility Project

Get the No Burn-Through Elbow eGuide to learn many reasons why Champion Fiberglass elbows will enhance your data center and utility projects today.

Considerations for Direct Burial Conduit

Installation type plays a key role in the type of conduit selected for electrical systems in industrial construction projects. Above ground, below ground, direct buried, encased...

How to Calculate Labor Costs

Most important to accurately estimating labor costs is knowing the approximate hours required for project completion. Learn how to calculate electrical labor cost.