ECN Forum Forums Code Related Discussion NEC & other Code issues Spliced Neutral?

NEC is quite clear about soldered connections being electrically and mechanically secure *before* applying solder. This is impossible with tape or anything else applied *after* the solder connection is made.

If a simple twist suffices as the primary electrical and mechanical connection (is this in NEC anywhere? If so, then tape for insulation should be fine. But a twist is not sufficient for ground wires without a crimp ring or other listed device, so I don't see how it would be acceptable here, either.

The twist gives mechanical connection, the solder gives electrical connection (like the crimp ring). Where is the confusion.
The insulation has nothing to do with the electrical connection so it is not part of that equation. Insulation is another step, just like taping up a split bolt.

But where is twisting allowed as an approved connection?

"Twisting" is the same thing a wire nut does IMO

Twisting is implicitly allowed by 110.14 because what constitutes a "mechanically and electrically secure" connection isn't explicitly defined and twisting is not specifically prohibited.

So any soldered splice that is mechanically and electrically secure before soldering is approved and twisting is just one means to that end.

But it is sufficient

250.8 Connection of Grounding and Bonding Equipment.
Grounding conductors and bonding jumpers shall be
connected by exothermic welding, listed pressure connectors,
listed clamps, or other listed means. Connection devices
or fittings that depend .........SOLELY ON SOLDER........ shall not be used.

Twisted together and soldered is different than relying solely on solder.

There are a lot of things not specifically prohibited by NEC that aren't legal. NEC is always very clear about requiring LISTED connectors, clamps and other devices. Twisting may be common, but unless we expand 110.14 as carte blanche to use any method we feel like including unlisted knock-off products and home brew bolts, etc, it's not authorized.

I have yet to see anything in NEC authorizing twisting + solder beyond 90.2.(C). Not that 90.2.(C) isn't plenty for most jurisdictions, but it's not the same as actual code allowance.

Not to mention there are other factors involved- the difficulty of reversing such a splice, for instance. Might not be an issue if you've got 3' of slack in a panel as you can just cut it off, but what if every connection in a 2x4 outlet box was made up in this fashion?

Steve,

110.14(B)specifically permits a soldered connection.

"Twisted and taped" does seem pretty secure, electrically, if done well. That is not how I would do things but I removed dozens of splices made that way when I ripped out all the previous owner's work in this house and it was at least 20 years old. (dating from a 1978 remodel as best I can tell) I didn't find any traces of heating, even on the 1440w bathroom heaters.

Steve, I think you've got it backwards.

Splicing, by twisting and solder, is the standard by which all else is judged. That is, other connectors are listed as a substitute for this, the original accepted method.

All else - wire nuts, split bolts, PGC's, NSI's, crimps, whatever ... came later.