Ecmweb 4746 1001767web
Ecmweb 4746 1001767web
Ecmweb 4746 1001767web
Ecmweb 4746 1001767web
Ecmweb 4746 1001767web

What's Wrong Here?

Sept. 13, 2007
Hint: Sand is glass now.

How well do you know the Code? Think you can spot violations the original installer either ignored or couldn't identify? Here's your chance to moonlight as an electrical inspector and second-guess someone else's work from the safety of your living room or office. Joe Tedesco, who has a knack for finding shoddy electrical work, did the dirty work and found this mess. Now it's your turn to identify the violation.

Find the Answer

Donald W. Zipse, a well-known forensic engineer and engineering consultant to the electrical industry, sent in this photo that was taken inside a cottage basement out on Cape Cod, Mass. “The two ground rods had a resistance reading of approximately 600 ohms,” said Zipse. “One rod revealed a reading of 900 ohms! I could not get around the other rod to take a measurement, however, calculations for the second rod resulted in a 1800 ohm value.”

There are two things wrong with this installation.

  • The rods were driven into desert dry soil. Since the rods were located in the basement there was no water available to wet the soil.
  • Assuming the rods were 8 feet long, the two rods were electrically acting as one. To obtain the maximum grounding effect, the distance between the rods must at least be the depth of the first rod, plus the depth of the second rod. Thus, the rods should be spaced no closer than 16 feet apart. This requirement can be found in the Institute of Electrical and Electronic Engineers (IEEE) Standard 142, The Green Book.

This installation is also a tripping hazard!

> Try Another Quiz

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.

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