Ecmweb 4764 Dsc00137web
Ecmweb 4764 Dsc00137web
Ecmweb 4764 Dsc00137web
Ecmweb 4764 Dsc00137web
Ecmweb 4764 Dsc00137web

What's Wrong Here?

March 27, 2007
Hint: A potentially shocking installation

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

Answer:

Although it is acceptable to run this underground rigid metal conduit up this tree as per 410.16(H) and 300-5(D)(4), the improper support and broken liquidtight flexible metal conduit is a hazard. The separation creates a lost equipment ground, which could allow the equipment on the load end of this circuit to carry electrical current. In turn, this could lead to an electrical shock.

Here are some NEC rules you should be familiar with when using vegetation as a means of support for electrical circuits.

  • 225.26 (Services) Vegetation as Support. “Vegetation such as trees shall not be used for support of overhead conductor spans.”
  • 230.10 (Services) Vegetation as Support. “Vegetation such as trees shall not be used for support of overhead service conductors.”
  • 410.16(H) (Means of Support) Trees. “Outdoor luminaries (lighting fixtures) and associated equipment shall be permitted to be supported by trees.
    FPN No. 1: See 225.26 for restrictions for support of overhead conductors.
    FPN No. 2: See 300.5(D) for protection of conductors.
  • 300.5(D)(4) (Underground Installations) Enclosure or Raceway Damage. “Where the enclosure or raceway is subject to physical damage, the conductors shall be installed in rigid metal conduit, intermediate metal conduit, Schedule 80 rigid nonmetallic conduit, or equivalent.”
  • 590.4(J) (Temporary Installation) Support. “Cable assemblies and flexible cords and cables shall be supported in place at intervals that ensure that they will be protected from physical damage. Support shall be in the form of staples, cable ties, straps, or similar type fittings installed so as not to cause damage. Vegetation shall not be used for support of overhead spans of branch circuits or feeders.”
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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