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. Can you identify the Code violation(s) in this photo?
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Hint: Two for one?
‘TELL THEM WHAT THEY'VE WON…’
Using the 2008 NEC, correctly identify the Code violation(s) in this month's photo — in 200 words or less — and you could win something to put in your tool-box. E-mail your response to firstname.lastname@example.org, and he'll select three winners (excluding manufacturers and prior winners) at random from the correct submissions. Winners will receive a set of insulated hand tools from Ideal Industries, Inc., valued at more than $125.* The set includes 9.25-in. insulated side-cutting pliers, 10-in. insulated tongue-and-groove pliers, and a 0.25-in. × 6-in. insulated screwdriver. (* Please allow six to eight weeks for delivery of tools.)
Our three winners this month were: Ralph Averill, electrician, Northeast Tradesman, New Preston, Conn.; Michael Snyder, VP, Laser Electric Co., Peoria, Ill.; and Patrick Dillon, E&C technician, Virginia Commonwealth Univ., Richmond, Va.
This was a hard one to deal with because the size of the parallel conductors doesn't clearly reveal whether or not these are service or feeder conductors. If these are service conductors, then the proper size bonding jumper is determined in accordance with 250.102(C) and Table 250.66. However, if they are actually feeder conductors, the minimum size equipment bonding jumper on the load side of the service is regulated by 250.102(D).
As covered in 250.102(D), “The equipment bonding jumper on the load side of the service overcurrent devices shall be sized, as a minimum, in accordance with the sizes listed in Table 250.122, but shall not be required to be larger than the largest ungrounded circuit conductors supplying the equipment and shall not be smaller than 14 AWG.” These parallel, 3/0 copper conductors, which make up a 600A feeder, require the use of a No. 1 AWG copper or 2/0 aluminum conductor.
Another violation we can cite is the routing path and size of the equipment grounding conductor. As given in 250.122(F), “Where conductors are run in parallel in multiple raceways or cables as permitted in 310.4, the equipment grounding conductors, where used, shall be run in parallel in each raceway or cable. Each parallel equipment grounding conductor shall be sized on the basis of the ampere rating of the overcurrent device, protecting the circuit conductors in the raceway or cable in accordance with Table 250.122.” As was the case for the bonding jumper, a minimum No. 1 AWG copper or 2/0 aluminum equipment grounding conductor would be required in each conduit.
The last concern is how the lay-in lugs are being used. If these lugs are listed for a single conductor, then the termination of multiple conductors on a single lug is a clear violation of 110.3(B).