: > 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
: > 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
: > (14AWG). I coated the ends with solder and then bend them to
: > before connecting them to standard outlets (screwed on, not
: > in). Will this cause any problems or break any electrical
: > located in Ontario, Canada in case that matters).
: > The reason why I'm asking is because I've been doing a whole
: > reading about issues with aluminum wire, one of the issues
: > thermal expansion problems caused by the aluminum wire
expanding at a
: > different rate than the screw connector it's connected to on
: > outlet/switch/etc. So this made me wonder if the solder will
: > problems with thermal expansion of it being different than
: > 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
: 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
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<g>.
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.