Electrical: Joining Wires

[stretch]

Also, when you join a single stand wire to a solid you're supposed to first wrap the strand end around the solid wire, then bend the solid wire over the stranded wire.

If you bend the wires over like that, the wire nut won't work as well. A good quality wire nut has a spiral springinside it that squeezes the wires together and holds them under tension. If the wire nuts that came with the fixtures don't have springs in them, throw them away and go buy good wire nuts and use them. There are different size wire nuts, get the right size for the wires that you are using. There is usually a chart on the box showing how many of each size that you can join with each wire nut. There are grounding wire nuts (Green) that have a hole in the end. You leave one solid wire long, it goes through the end. After you tighten the wire nut, the exposed wire end goes around the ground screw.

Stretch

[Wes Stebbins]

I'm installing PS 1/PS 5 Air Seal Recessed Housing from Thomas Lighting (purchased from Menards). I have two basic questions concerning the joining of wires when wiring up these lights.

1) I know when you join two solid wires together you're supposed to wind them clockwise around each other. Also, when you join a single stand wire to a solid you're supposed to first wrap the strand end around the solid wire, then bend the solid wire over the stranded wire. My question, then, is what do you do when you have two solid wires and 1 stranded wire to connect together.

2) Also, concerning the particular lighting described above, when connecting additional outl, a contractor friend of mine attaches (wraps) both ground wires together, and then sends them back up through the knockout - as opposed to doing what the directions say, namely, hook the ground to the green wires, etc. What is the correct way to do this (or are they both ok?), as well as advantages/disadvantages to each?

Thanks,

Wes

[RBM]

[nobody]

Use a good wirenut, do not "fold" any wires back. When joining stranded to solid wire, leave the stranded wire about 1/16 longer than the solid, and twist the wirenut on firmly. pull on the individual wires to make sure they are connected well. Do not just shove the ground wires thru a knockout. wirenut them to the ground wire in the fixture, or run a pigtail to the grounding screw. you want to make sure that the ground wires are secured well.

[RMUH]

As has already been mentioned, the correct method is to follow the instructions for the particular brand of connector you are using. Personally, I make it a point to use the kind that don't require (indeed are compromised by) the twisting. The only thing special about joining stranded wire (or smaller wire) to a solid wire is to let the stranded (or smaller) wire protrude into the connector a tiny bit (maybe 1/16 inch) further into the connector. Also, some types are better at joining solid wires, and others are better when all the wires are stranded. Bottom line: follow the instructions.

Not sure what you mean by "sends them up through the knockout", but if this means the ground wires protrude outside the fixture wiring box, then it is just plain wrong, and is a violation of the NEC. The fixtures you have are well designed and approved by the appropriate agencies to be installed according to the instructions that came with the fixture. Don't invent stuff even if it does get the lights to work. It never saves any significant amount of either time or money.

[Wes Stebbins]

So, then, to expand my original questions

1) Is there not a "specific" technique for wiring 1 stranded wire to two solid (14 gage) wires? (Of course, by "two solid" I mean the light's white stranded wire to two white wires - one coming in, one going out - the same for the black and ditto for the grounds.

2) Is either method for the ground wires ok, i.e., (a) my contractor/friend's running the solid ground wires back up throught the knockout (not even connecting to the light's green wire ground, but the two solid ground wires, of course, touching the light's metal box in the process) vs. (b, per instructions for the lights) connecting the two solid ground wires to the light's green wire?

Thanks again,

Wes

[Robert Barr]

I have never trusted stranded wire connetions. I've seen too many go bad (mainly from corrosion over time) & cause problems. I solder. It takes a few extra minutes, but in my view, it's always worth it.

If you want something that can be taken apart later, you can also 'tin' the stranded ends (with solder), effectively making them solid. That gives the wire nut something to dig into, and keeps the corrosion in check.

[Doug Miller]

Note, however, that the National Electrical Code requires that a mechanical fastener (such as a wire nut) must be used _in_addition_ to the solder. A connection made by solder alone is a Code violation.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[Robert Barr]

I always add a wire nut, but not for NEC -- more like sloth. It's difficult to insulate the connection otherwise. Almost impossible with just electrical tape.

I've examined the solder-dipped connections on my home (65 y.o.), and it takes all day to pull off the fabric / tar taping. I have to use pliers. Those guys didn't screw around, which is the way I like it, but the connections are huge, about the size of my thumb or better. A wire nut is so much easier...

[Bert Byfield]

What about electrical tape wrapped around a soldered connection? Is that a "mechanical fastener"? It insulates the connection, at least.

[Doug Miller]

No.

That's not the point. The Code requires that the connection be mechanically and electrically secure even _without_ the solder. You can't achieve that with tape.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[HorneTD]

Can you quote me chapter and verse on that assertion. I am unaware of any such provision in the code except that "Connections depending solely on solder shall not be used" in attaching Equipment Grounding Conductors to boxes. A splice that is made up mechanically and then soldered is perfectly acceptable as is shown by the reference in 250.148 to 110.14.

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. ... 110.14 Electrical Connections. Because of different characteristics of dissimilar metals, devices such as pressure terminal or pressure splicing connectors and soldering lugs shall be identified for the material of the conductor and shall be properly installed and used. Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use. Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.

(B) Splices. Conductors shall be spliced or joined with splicing devices identified for the use or by brazing, welding, or soldering with a fusible metal or alloy. Soldered splices shall first be spliced or joined so as to be mechanically and electrically secure without solder and then be soldered.

-- Tom H

[masterelectrician]

The only 100% safe electrical connection is to stick the ends of the wire in a porcelain cup. Then fill the cup with 99.9% pure molten copper. When the copper had cooled, remove the cup and coat the entire connection with pure liquid rubber, forming a minimal thickness

1/4" around the entire joint. When the rubber dries, (generally 3 to 7 days), wrap the entire connection with at least 10 layers of friction tape, followed by several layers of vinyl electrical tape. Be sure the liquid rubber and all tapes extends at least six inches past the joint into the insulation. Carefully place these connections into the electrical box, being sure that there is at least 1/8" gap between the taped joints. To complete the joint, fill the entire electrical box with epoxy, and allow it to harden thoroughly before turning on the power. Note: You can not use standard electrical boxes, they are too small. You must use a cast iron or solid molded brass box that is at least 12 inches long and 5 inches wide by 4 inches deep for every two wires (plus ground), you connect. If there are more than 2 wires (plus ground), or the wire is thicker than a #12 gauge, you must increase the box size. If you are mounting the box on a ceiling, it is not possible to fill it with epoxy. Therefore you must pre-connect everything on the floor, then attach the wire and boxes to the ceiling.

This new connection method will be required by law by the NEC, starting in 2007. All structures that presently have wirenuts or any other connection method will be required to rewire prior to January 1,

2008. Anyone not complying with this law will be fined or imprisoned, and their home or other structure will be condemned and demolished immediately. This law is being enacted to protect insurance companies so they can make more profit. An alternative solution is currently under development in which all wires will be replaced with solid copper insulated "sticks" which will be threaded on the ends and screw into fittings, very similar to threaded plumbing pipe. All current electrical receptacles, fixtures and other devices will be phased out and instead of using screws, these devices will have threaded connections.

Master Electrician

[Waldo]

Actually, this means that the wires should be twisted together to make a solid connection prior to being soldered as opposed to just having the wires next to each other and soldered. The twisting together makes the joint mechanically and electrically secure.

Waldo

[genepitney]

If you apply a cutting torch to the wirenut, it would probably get hot enough to allow you to apply the solder. The only problem i see with this method is that the wire testicle would burn off it's insulating part and only leave the little springy thingy on the wire, plus you'd probably have to tape all of the wires for a few feet because of all the burned off insulation. But if thats what it takes to comply with the law, the hell with common sense. You know the law is always right,

[Doug Miller]

That, of course, is _exactly_ what I said: a mechanical fastener must be used in addition to the solder. And you cited the relevant portion of the Code yourself:

[...]

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[Doug Miller]

But twisting together *without* solder is not an approved method of making a splice - and since the splice must not rely on solder to be either mechanically or electrically secure, the addition of solder cannot transform an unapproved splice into an approved one.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[HorneTD]

Doug I was trying to draw a difference between what you were saying and what the code actually requires. I now understand that you believe that the code forbids traditional soldered splices. I don't believe it does and when I have had to do repairs and extensions of knob and tube wiring I have made up mechanical splices by twisting or wrapping the conductors around each other in the traditional manor creating at least three full turns, then soldered, followed by taping. So far I have passed inspection. I would like you to tell me how you would solder a splice that is already covered with a solderless connector. The language of section 110.14 requires that the conductors be spliced or joined first and then soldered.

I think I'll just continue to use the traditional method, were it is appropriate, and if an inspector ever refuses it I'll see what the state board of appeals has to say. You see if your position were correct it would be absolutely pointless to use solder. I have to believe that the code making panel did not put in language on soldered splices just to render the practice useless. If that was the intention they would have simply forbid the use of soldering as a splicing technique.

-- Tom H

[Noozer]

1. Strip wires
2. Use wirenut to twist & join wires
3. Remove wirenut
4. Solder the tightly twisted wires
5. Add wirenut back

Done

[Doug Miller]

If by "traditional soldered splices" you mean twisted together, soldered, and taped, yes, I believe that *is* prohibited. Making a splice by twisting and taping, *without* solder, is *not* an approved method of making a splice. Since the Code *also* requires that splices not depend on solder, it's hard to imagine how the addition of solder to an unapproved splice could transform it into an approved splice.

Passing inspection is not necessarily the same as being Code-compliant. :-)

That language does not, however, require the use of any one specific type of connector. As I read that, the Code would approve the use of a split-bolt connector, for instance (making the splice mechanically and electrically secure), followed by solder, followed by tape.

The Code *does* forbid the use of soldering as a splicing technique. That's what it means when it says that the connection shall be mechanically and electrically secure without solder: that soldering, alone, as a splicing technique, is forbidden, but _in_conjunction_ with other, approved methods it is permitted.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?