Ecmweb 6587 Nec Illustrated Catastrophes Pr
Ecmweb 6587 Nec Illustrated Catastrophes Pr
Ecmweb 6587 Nec Illustrated Catastrophes Pr
Ecmweb 6587 Nec Illustrated Catastrophes Pr
Ecmweb 6587 Nec Illustrated Catastrophes Pr

Illustrated Catastrophes: Don't Flip That Switch

Aug. 18, 2014
More Code catastrophes uncovered and corrected in these faulty installations

All references are based on the 2014 edition of the NEC.

Emergency Feeder Foul

This generator and temporary wiring was being used to provide temporary emergency power to a high-rise apartment building after the on-site backup generator failed. Section 590.3 permits temporary power for emergency situations; however, more care should have been taken when setting up this equipment.

The general rules of 590.4 require cables or cords to be used for temporary feeders. The Exception allows single insulated conductors to be used for this situation if the wiring is accessible to qualified people only. These wires are installed in a parking lot and also near a busy stairway.  As you can clearly see, the installer made virtually no attempt to protect these conductors or prevent the general public from stepping right on top of them. The plywood with the bag of cement on top was a lame attempt at providing protection and separation. Tying the caution tape to the shopping cart was another failed idea because the cart simply rolled away, leaving the caution tape lying on the ground. Section 590.4(J) now prohibits cables and cords from being laid on the ground, but ironically does not prohibit single insulated conductors from being laid on the ground.

Don’t Flip That Switch!

Dave Shaub, vice president of operations for ATS Electric in Phoenix, was kind enough to share this great photo with us. Shaub says, “We had to get into the existing electrical room to turn off the power for the site lighting. We opened the contactor box and found the switch controlling the coil mounted this way.”

Installing a switch in this way is a violation of 404.3(A), which states that switches “must be of the externally operable type mounted in an enclosure listed for the intended use.” This snap switch is designed to be flush mounted in a device box or similar enclosure. This is also certainly a violation of 110.3(B), since the switch is not designed to be installed or used in this way.

I’m assuming the piece of cardboard behind the switch was an attempt at installing some type of insulating material between the switch and the grounded metal enclosure, since there is really no clearance for the wires leaving the terminals due to the way this switch is mounted. This is an electrical explosion waiting to happen, since the cardboard is no guarantee as an electrical insulator.

About the Author

Russ LeBlanc | Owner

Russ started in the electrical trade as an apprentice in 1985. He worked his way up to become a Journeyman Electrician and then eventually became a Master Electrician and Licensed Construction Supervisor. In 1999 Russ become an Electrical Instructor for The Peterson School of Engineering in Massachusetts where he developed his passion for teaching, and quickly became Department Head of Electrical Instruction. Russ has taught thousands of apprentices, electricians, engineers, inspectors, and other electrical professionals during his career as an instructor. He continues to provide electrical professionals with Electrical Code seminars, Arc-Flash Awareness training seminars and educational material through his LeBlanc Consulting Services in North Reading, MA whose specialty is educating electricians. He has been an active member of the NFPA Electrical Section and has authored hundreds of National Electrical Code proposals and comments which have become Code rules to improve the safety for the electrical industry. Russ is also an IAEI certified Electrical Inspector.

Please visit www.russleblanc.net for more information.

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