Soldered splices

[480sparky]

The solder increases the contact area between the two (or more) conductors.

So how does it do this? Does it melt or somehow else distort the copper?

 

[MAC702]

So how does it do this? Does it melt or somehow else distort the copper?

In much the same way as the conductive spring of a wirenut also does this.

 

[GoldDigger]

" Connections depending solely on solder shall not be used. "

There is a big difference between the above statement and the casual statement that the connection "must be mechanically and electrically secure before soldering."

I can loop a wire through a terminal or twist two solid conductors together to get a mechanical travel limit (such as in the Western Union splice) and some electrical continuity without having a good constant electrical connection before I apply the solder. I just cannot butt two wires together in a blob of solder though.

One test would be whether the connection (terminal or splice) could simply come apart under moderate tension if the solder were melted.

Another would be whether the wires/parts were touching each other or not before the solder was applied. A thought experiment along this line would be two wires joined mechanically by a classic ceramic insulator and not touching at all (like an insulated joint in a guy wire). Just adding a bridge of solder over the surface of the insulator would also not be acceptable.

 

[DBoone]

" Connections depending solely on solder shall not be used. "

There is a big difference between the above statement and the casual statement that the connection "must be mechanically and electrically secure before soldering."

I can loop a wire through a terminal or twist two solid conductors together to get a mechanical travel limit (such as in the Western Union splice) and some electrical continuity without having a good constant electrical connection before I apply the solder. I just cannot butt two wires together in a blob of solder though.

One test would be whether the connection (terminal or splice) could simply come apart under moderate tension if the solder were melted.

Another would be whether the wires/parts were touching each other or not before the solder was applied. A thought experiment along this line would be two wires joined mechanically by a classic ceramic insulator and not touching at all (like an insulated joint in a guy wire). Just adding a bridge of solder over the surface of the insulator would also not be acceptable.

What is a “mechanical Travel limit”

 

[K8MHZ]

" Connections depending solely on solder shall not be used. "

There is a big difference between the above statement and the casual statement that the connection "must be mechanically and electrically secure before soldering."

That's not just a casual statement, it's part of 110.14 "Soldered splices shall first be spliced or joined so as to be mechanically and electrically secure without solder and then be soldered"

 

[MAC702]

What is a “mechanical Travel limit”

Something that provides resistance to movement by physical means. Twisting the wires together provides a mechanical travel limit. Soldering it afterward makes it much better.

 

[480sparky]

In much the same way as the conductive spring of a wirenut also does this.

Is the spring of a wirenut considered an electrical part of the circuit?

 

[Adamjamma]

In my own mind, yes.. much like a crimp joint or a spring joint like used in the back fed outlets or the ideal and wage nuts... the plastic of the nut is an insulator that can actually burn off before the metal part releases the joint... so hopefully the joint is not the source of any fire...

 

[steve66]

As far as I'm aware, simply twisting two wires together does not create a code compliant electrical connection.

So unless someone can show me where it says that does make a valid connection, I'm going to say as far as I'm concerned, a soldered joint is not allowed.

 

[MAC702]

Is the spring of a wirenut considered an electrical part of the circuit?

Is the screw on the side of a receptacle?

 

[MAC702]

As far as I'm aware, simply twisting two wires together does not create a code compliant electrical connection.

So unless someone can show me where it says that does make a valid connection, I'm going to say as far as I'm concerned, a soldered joint is not allowed.

Non sequitur. It's not Code compliant until it's soldered. But it is electrically and mechanically connected at that point.

Twist the wires together and they will conduct some measure of electricity and hold themselves together somewhat. But to make it a much better connection, you then either solder them or compress them together inside a wirenut to be Code compliant, and much more permanent.

 

[480sparky]

Is the screw on the side of a receptacle?

Yes. Now answer my question.

 

[480sparky]

Non sequitur. It's not Code compliant until it's soldered. ........

You mean even using wire nuts, the joint must be soldered?

 

[MAC702]

Yes. Now answer my question.

You just did.

 

[MAC702]

You mean even using wire nuts, the joint must be soldered?

I apologize if the "OR" wasn't implied well enough throughout the entire thread.

Especially since it was specifically used in the section of my post that you quoted and deleted for brevity.

 

[jwnagy]

I believe that just one wrap of tape has at least a 600 volt insulation value.

The section of the code I quoted from uses the word equivalent. Does electrical tape alone meet that requirement? Does it have all of the equivalent characteristics of the wires insulation?

It has to be more than voltage rating.

 

[ptonsparky]

The section of the code I quoted from uses the word equivalent. Does electrical tape alone meet that requirement? Does it have all of the equivalent characteristics of the wires insulation?

It has to be more than voltage rating.

I always took it as equivalent in thickness, as well as insulation value.

 

[MAC702]

The section of the code I quoted from uses the word equivalent. Does electrical tape alone meet that requirement? Does it have all of the equivalent characteristics of the wires insulation?

It has to be more than voltage rating.

This is a very good question, but it could also be applied to the wirenut.

 

[Frank DuVal]

It has to be more than voltage rating.

If you use different insulation conductors in the same circuit, only the voltage (OK, and temperature) rating of the conductor needs to be sufficient for the circuit. So, the only rating of the added insulator at the junction just has to meet voltage and temperature. Thickness does not matter, as long as the first two are met.

I see from the 3M spec sheet for 33+. it is 7 mils thick. The dielectric strength of 33+ is 1150 V/Mil, so test would be 8050 volts per wrap! However, it is only given a 600 volt rating by UL510 test. One or 100 wraps......

One layer of most heat shrink is also 600 volts.

So you are good to go from a voltage perspective of one wrap. Good practice might use more wraps.....

 

[Frank DuVal]

ignore the 'do not place solder on the iron'

The instruction was to not to carry the solder to the joint on the iron. Meaning ALL the solder for the joint, no added solder from a roll, etc.

Yes, wetting the iron is proper, otherwise you will not get the job done today....

Also proper use it to add solder to the iron when placing it back in the holder, when you take the iron from the holder, wipe the tip on a sponge or "Curly Kate" to expose fresh (non-oxidized) solder, re wet and solder the part. Enough electronics instruction for the day!