Sometimes a code change is made with no supporting comment—no technical support —other than “we have been doing it this way for years and have had no trouble.” Section 4-3.3(d) of the NFPA Requirements Governing Committee Projects requires that substantiation be provided for each proposal.
The statement that, “We have been accepting this code violation for ___ years,” hardly qualifies as substantiation. The required substantiation for a code change is expected to be technical in nature. However, here are a few prospects for future change proposals:
“250-64. Grounding Electrode Conductor Installation. (b) Grounding Electrode Conductor. A grounding electrode conductor or its enclosure shall be securely fastened to the surface on which it is carried. A No. 4 copper or aluminum, or larger conductor shall be protected if exposed to severe physical damage.
A No. 6 grounding conductor that is free from exposure to physical damage shall be permitted to be run along the surface of the building construction without metal covering or protection where it is securely fastened to the construction; otherwise, it shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor. Grounding conductors smaller than No. 6 shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor.”
Flexible metal conduit is nowhere in this list, yet most of the dry transformers establishing separately derived systems are connected with flexible metal conduit. Here, general practice supersedes code requirements. The reference establishing that this Section applies to separately derived systems is found in Section 250-30-(a)(4).
Would this qualify for a code change proposal permitting flex on the basis of long-time use?
The requirements for splicing in Surface Metal Raceways not having a removable cover are found in Section 352-7. Identical requirements appear in 352-29 for Surface Nonmetallic Raceways:
“352-7. Splices and Taps. Splices and taps shall be permitted in surface metal raceways having a removable cover that is accessible after installation. The conductors, including splices and taps, shall not fill the raceway to more than 75 percent of its area at that point. Splices and taps in surface metal raceways without removable covers shall be made only in junction boxes. All splices and taps shall be made by approved methods.”
Why the restriction to junction boxes for splices and not outlet boxes? This is another code requirement that is generally ignored in the field. An outlet is defined in Article 100 as “A point on the wiring system at which current is taken to supply utilization equipment.” In a surface raceway system this would generally be a receptacle or lighting outlet. A junction box is not defined in the Code.
In the index under “Boxes,” is the entry “Junction, pull see Junction boxes,” and under “Junction boxes” appears: “see also Boxes; Pull boxes.” Under “Pull boxes” appears: “see also Boxes; Junction boxes.” Well, that merry-go-round ride is really not necessary, is it, for we all know what a junction box is, and in the usual surface raceway system it would also be a switch box. Is there an electrician who would not make a splice in a receptacle or fixture outlet box because the Code prohibits it? I doubt it.
Would this qualify as a code change proposal to permit splices in outlet boxes because we have been doing it for years without any problems?
This one is more of a UL requirement, but also comes under NEC Section 110-3(b), which brings UL requirements into the Code, and also Section 110-14(b) “Splices,” and it concerns split-bolt wire splicing means. In the 2000 UL White Book on page 118 appears: “Pressure cable connectors are for general use and are designed to establish a connection between one or more conductors by means of mechanical pressure without the use of solder.
Pressure cable connectors accommodate two solid and/or stranded wires unless otherwise noted on or in the shipping carton or on the connector.” The catalogs of every major manufacturer of split-bolt connectors show that they are intended for no more than two wires, usually designated as “run” and “tap.” My observation is that very often a split-bolt connector splices more than two wires.
Would this qualify for a code change proposal based on years of misuse? If you have evidence of a failure due to this misuse, please let me know.
SCHWAN is an electrical code consultant in Hayward, Calif. He can be reached at firstname.lastname@example.org.