Does coating stranded copper wire with solder cause any issues or break any codes?

Does coating stranded copper wire with solder and then connecting it to
a standard outlet cause any issues or break any codes?
I have a small project I put together (this is all inside of a big box
... ie: not inside a wall or part of the house ... but I still would
like to make sure it's safe and meets any code requirements as if it
was inside a wall or part of the house) which uses stranded copper wire
(14AWG). I coated the ends with solder and then bend them to shape
before connecting them to standard outlets (screwed on, not the push
in). Will this cause any problems or break any electrical codes (I'm
located in Ontario, Canada in case that matters).
The reason why I'm asking is because I've been doing a whole bunch of
reading about issues with aluminum wire, one of the issues being the
thermal expansion problems caused by the aluminum wire expanding at a
different rate than the screw connector it's connected to on an
outlet/switch/etc. So this made me wonder if the solder will cause any
problems with thermal expansion of it being different than the screw
that it's screwed on to, etc.?
Thanks for any info you share,
Harry
Reply to
Harry Muscle
Loading thread data ...
back before the advent of 'solid state' and 'Printed circuit boards' all electronics, even high power devices, used copper wires that were 'tinned' with solder before being attached to screw terminal strips. it was the 'professional way of doing it.
as an electronics guy, I still 'tin' all wires I'm going to be soldering.
"tinning" means putting a coating of heated solder over the bare wire PRIOR to making the final solder connection.
Reply to
FireBrick
The only prohibition is against a connection that depends on the solder; you could not solder the wire to the outlet because the screw fell off. Using solder for convenience, as you have, is fine. I usually crimp fittings on stranded wire.
Now, your box project is suspect; but you didn't ask about that.
Reply to
Toller
You should not solder stranded wire prior to putting it into a screw terminal. Solder creeps under pressure, so the contact pressure will steadily reduce over time until it forms a bad contact. Strands which are tinned during the cable manufacture are OK, as the solder layer thickness is controlled and very thin. I'm not familiar with your local regulations, but in cases of stranded wire connecting to terminations which don't work well with stranded wire, the normal method is to crimp on a bootlace ferrule or an eyelet, depending on the terminal style.
Reply to
Andrew Gabriel
The only place I ever use stranded wire with screw terminals is in a lamp, and I have on occasion tinned the end first.
I find the creep problem very bad and screws and stranded wire are a bad mix. I have had a few instances where #14 or #12 stranded wire was pulled through a conduit, so instead of trying to attach it to a screw terminal, I would pigtail a short piece of solid wire to it and attach it to the terminal.
That reminds me of a lecture I once attended. The speaker was telling of an experience with a company he was working with back in the 1960s when they got a project related to the space program. They all had to be "schooled" in procedures such as soldering, which seemed beneath them at the time.
The thing that stuck out in my mind was part of NASA's standards: when a stranded wire was tinned or soldered to a terminal, you should still be able to count how many strands it has.
Reply to
Calvin Henry-Cotnam
: In article , : "Harry Muscle" writes: : > Does coating stranded copper wire with solder and then connecting it to : > a standard outlet cause any issues or break any codes? : > : > I have a small project I put together (this is all inside of a big box : > ... ie: not inside a wall or part of the house ... but I still would : > like to make sure it's safe and meets any code requirements as if it : > was inside a wall or part of the house) which uses stranded copper wire : > (14AWG). I coated the ends with solder and then bend them to shape : > before connecting them to standard outlets (screwed on, not the push : > in). Will this cause any problems or break any electrical codes (I'm : > located in Ontario, Canada in case that matters). : > : > The reason why I'm asking is because I've been doing a whole bunch of : > reading about issues with aluminum wire, one of the issues being the : > thermal expansion problems caused by the aluminum wire expanding at a : > different rate than the screw connector it's connected to on an : > outlet/switch/etc. So this made me wonder if the solder will cause any : > problems with thermal expansion of it being different than the screw : > that it's screwed on to, etc.? : : You should not solder stranded wire prior to putting it into : a screw terminal. Solder creeps under pressure, so the contact : pressure will steadily reduce over time until it forms a bad : contact. Strands which are tinned during the cable manufacture : are OK, as the solder layer thickness is controlled and very thin. : I'm not familiar with your local regulations, but in cases of : stranded wire connecting to terminations which don't work well : with stranded wire, the normal method is to crimp on a bootlace : ferrule or an eyelet, depending on the terminal style. : : -- : Andrew Gabriel
I know that, at least on Ottawa, and I imagine most places, you cannot tin wires to be used where an electrical inspecation is necessary. Same in the states. No, I cannot cite NEC, so no use asking. The reasons are exactly as Andrew pointed out. Solder compresses and deforms to whatever force is applied to it and as soon as air creeps in, there is corrosion, moisture, etc etc etc., not to mention the affects of vibrations, etc.. How do I know? I got to see a connection that failed, then started to heat (high currents) and the solder dripped out of the connection onto the wireing below it. No, it's not a horror story, but the melted solder wasn't too cute inside the box. Whoever installed it didn't know the first thing about tinning, besides it not being acceptable to do; he had the wiring well "blobbed" with sodler. I think I understand why you want to tin it, but properly dressed stranded wire will work perfectly under appropriate screw heads. If it's a permanent install, I'd modify it accordingly, again along the lines of Andrew's suggestions. He's right on.
Pop
Reply to
Pop
Reminds me of ET-Maintenance school in the military. Spent literally a *week* learning/practicing on just how to solder to bi-furcated and turret terminals.
We too had to be able to count the strands after tinning. And how much insulation to strip off so that no more than 2 mm of conductor was exposed after attaching to terminal. And no melted insulation, and... and... and... There was something like 14 checks for each soldered terminal connection.
Was bad enough on the bench, but then doing it laying on your back reaching up inside a cabinet with just a drop-light to see by. Now *that* was fun (NOT!!!).
daestrom
Reply to
daestrom
damn, I remember having to go through that course back in the early 80's working with a defense contractor, was really hard. Their standards are very tough, for a good reason of course.
Reply to
MC
I remember those too, And all thsoe damn hand cramps trying to hold everything steady while soldering upside down with arms reached up to the work and hoped you were good enough not to burn yourself.
Reply to
MC
I like a mechanical crimp to a terminal, but then followed up by soldering
My father used crimped connections on all his wiring on his house, then soldered and taped (no wire nuts, was done in 1970) All still works great. At time when having to replace an outlet or light switch, everthing was still pretty solid, but do intend on doing a preety thorough inspection soon including junction boxes in the attic.
Reply to
MC
The code says you can't make a connection that depends entirely on solder. It has to be a compression connection. Screws, bolting, clamping crimping etc. It's O.K. to solder after it's tight. I have heard of failed inspections because someone tinned stranded wire, then secured it in a solderless lug. The reasoning being that if it gets hot, the solder flows out, and it is then loose.That may be debatable, but I lean toward agreement on it.
Reply to
Long Ranger
The NEC says "electrically and mechanically secure". My understanding is that solid wires can stil be twisted then soldered as was the practice before wirenuts appeared.
---------------------- If tightly twisted wire was minimally tinned I would think the solder would hold the strands in place and the stress of clamping would be borne almost entirely by the copper. Do you still get cold flow?
bud--
Reply to
Bud--
The electric service panel in my house has long stranded ground wire held in two places by bolts. I dont think its tinned though. It is silver but I suppose it comes from the drop that way.
Reply to
dnoyeB
Are you talking about twisting, tinning, and using a wire nut, or skipping the wire nut? If skipping the nut, then I don't see it as a proper joint.
I twisted a #8 with two #12s and didn't think it looked particularly stable, so I soldered them before putting a wire nut on; but would never have considered not using the nut.
Reply to
Toller
:
: > L: >> The code says you can't make a connection that depends entirely on : >> solder. It has to be a compression connection. Screws, bolting, clamping : >> crimping etc. It's O.K. to solder after it's tight. I have heard of : >> failed inspections because someone tinned stranded wire, then secured it : >> in a solderless lug. The reasoning being that if it gets hot, the solder : >> flows out, and it is then loose.That may be debatable, but I lean toward : >> agreement on it. : > The NEC says "electrically and mechanically secure". My understanding is : > that solid wires can stil be twisted then soldered as was the practice : > before wirenuts appeared. : > : > ---------------------- : > If tightly twisted wire was minimally tinned I would think the solder : > would hold the strands in place and the stress of clamping would be borne : > almost entirely by the copper. Do you still get cold flow? : > : Are you talking about twisting, tinning, and using a wire nut, or skipping : the wire nut? If skipping the nut, then I don't see it as a proper joint. : : I twisted a #8 with two #12s and didn't think it looked particularly stable, : so I soldered them before putting a wire nut on; but would never have : considered not using the nut. : :
I've done that, too. In fact, I did our whole house in Chgo that way. Lucked out and got a factory's worth of stranded wire on spools for free just as I was prepping to rewire. And yes, it passed inspection easily, first time, with only a comment about a power strip I left plugged in downstairs.
Properly soldered, that would work. If you know how to do that, great. But if anyone thinks a solder joint is "good" because it looks nice and shiny and smooth, then go back to school because that wire nut's going to loosen up. Not many electricians know how to solder a joint that would accept a wire nut reliably (or any other similar fastening metod), and it would also require the metal spring type wire nut to be reliable. Something has to penetrate the solder coat to put pressure on the copper, not just on the solder. It's not as easy to accomplish for the inexperienced as one may think. Then, if they do get a good solder joint, they forget to use a heat sink and the insulation melts or burns on them.
Pop
Reply to
Pop
I wouldn't solder a connection then use a wire nut. My experience is that wire nuts are reliable when used within the manufacturer's range of wire combinations. And they have not been tested on soldered connections.
Twisted solid wire that is mechanically secure and then soldered was the standard method for making connections for many years before wire nuts. I have seen only 2 failed joints, both because the solder did not bond to one wire. As far as I know that is still NEC acceptable (but I wouldn't advocate doing it).
The question I asked was for a single tinned stranded wire in a pressure connection.
bud--
Reply to
Bud--
On Thu, 02 Feb 2006 11:55:00 -0600, Bud-- Gave us:
Stranded wire in a pressure connection cannot be soldered.
Reply to
Roy L. Fuchs
I am not doubting you, but can you give a reference for that? (I always crimp fitting on stranded, but was unaware of this prohibition...)
Reply to
Toller
It goes back to depending on the solder for the connection. The solder is holding the shape of the bundled strands. If it gets hot, it gets loose. You are depending on the solder to hold the pressure of the connector.
Reply to
Long Ranger
:
: > : > "Roy L. Fuchs" wrote in message : > news: snipped-for-privacy@4ax.com... : >> On Thu, 02 Feb 2006 11:55:00 -0600, Bud--
: >> Gave us: : >> : >>>The question I asked was for a single tinned stranded wire in a pressure : >>>connection. : >> : >> : >> Stranded wire in a pressure connection cannot be soldered. : > : > I am not doubting you, but can you give a reference for that? : > (I always crimp fitting on stranded, but was unaware of this : > prohibition...) : : It goes back to depending on the solder for the connection. The solder is : holding the shape of the bundled strands. If it gets hot, it gets loose. You : are depending on the solder to hold the pressure of the connector. : > : > : :
In other words, it's an interpretation of the standardS rather than a written rule?
Pop
Reply to
Pop

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.