Was it ever code complaint under the US NEC to join Equipment Grounding Conductors (EGCs) with only a mechanical splice made by twisting the wires without the use of a crimp or pressure connector.
250-114 in the 75 code says "Where more than one grounding conductor of a branch circuit enters a box, all such conductors shall be in good electrical contact with each other and the arrangement shall be such that the disconnection or removal of a receptacle, fixture or other device fed from the box will not interfere with or interrupt the grounding continuity".
That seems to make the common practice of simply twisting a few inches together, leaving a single stinger for the receptacle, legal at that time.
I've seen older installations in this area where 2 wire NM was used throughout the house, but a separate bare ground was run to the Kitchen receptacles. These separate grounds were typically just twisted together in the attic above (and I assume 1 went back to the panel).
Not if 110.14(B) was considered.
Tom- I think Joe is correct, at least back to the '68 code when I wrote my Masters. If your talking about sign building, and not the grounding conductor 600.42 allows just twisting the conductors together. If you've looked at these installations, there's no connectors or splicing devices on them. And that's legal today.
Many Thanks to all hands. A special thank you to Joe Tedesco for the specific section reference. Every time I run into this practice it is causing some sort of problem. When I was assisting with housing inspections it repeatedly caused elevated voltage drop on the ungrounded current carrying conductor / Equipment Grounding Conductor circuit. I have encountered it so many times that I began to think that it had to have been code compliant at some point in time.
On the sign issue are you saying that splices made by twisting the wires alone are code compliant in neon sign work? That seems so strange!
Tom- Don't I get a Special Thanks too? I gave you a code section. And yes, it's done all the time in the sign industry.
Well yes George you did but Joe's was on point to the original question. That splicing practice in sign construction is a real eye opener.
Up through 1968 equipment grounding conductors did not require a 'listed'connector or equivalent insulated covering (IMHO).
The 1968 language: 'All splices and joints and the free ends of conductors shall be covered with an insulation equivalent to that of the conductors.'
Since EGC were (and are) bare, an 'equivalent insulation' would be nothing.
In 1971 the language changed to add: 'or with an insulating device suitable for the purpose.'
In my opinion, this new language in 1971 brought about the requirement for some sort of connector for EGC's.
I have a question I've always wondered about:
In the US NEC, ground wires must be pigtailed. This is acceptable in Canada too, except that in the CEC (Canadian Electrical Code) it is also perfectly acceptable to terminate ground wires on the screws in the boxes.
So if you had 2 NM cable in a box, you can put one ground wire on the screw and cut it off, and the other one can run through the screw and attach to the device.
Seems to be pretty common to double up grounds on the screws too; a straight through connection on each side of the screw.
What is the just justification in the NEC for not allowing this? If there is one. Or, just any general opinions?
Strictly for grounding continuity, here is part of 250.148 that spells it out.
250.148 Continuity and Attachment of Equipment Grounding Conductors to Boxes.
Where circuit conductors are spliced within a box, or terminated on equipment within or supported by a box, any separate equipment grounding conductors associated with those circuit conductors shall be spliced or joined within the box or to the box with devices suitable for the use. Connections depending solely on solder shall not be used. Splices shall be made in accordance with 110.14(B) except that insulation shall not be required. The arrangement of grounding connections shall be such that the disconnection or the removal of a receptacle, luminaire (fixture), or other device fed from the box will not interfere with or interrupt the grounding continuity.
That quote I gave you from the 75 NEC was the official intrepretation of the PG county Md in 1978. I highlighted it in my book when the inspector pointed it out to me.
"Twisted" was what he said "shall be in good electrical contact with each other " meant.
I didn't see wirenuts om EGCs until I got to Florida.