Is it ok to solder the tips of stranded wire before inserting into a terminal block? I like soldering the tips so that there's no wire fraying or free strands. But...Does the solder slowly compress after awhile and the wire gets loose? Sure I could perhaps a crimp on pin terminals to stick in the terminal block. Ex:
-- D from BC British Columbia
Yes the solder will cold flow.
There are other crimp terminals such as Panduit
These can use standard lug crimpers.
Cheers
Does that apply to all solders? Is there a type of solder that takes a longer time to cold flow? Silver solder?
If you are going to put a (bare) wire under a screw, put that
*bare* wire under the screw. Don't "tin" it.I think there are even some safety regulations that directly address this issue (?)
Not sure, but I have come across this failure before.
Cheers
There's a chance that, if there's any motion or vibration, the wire will break at the transition between the wicked solder and the unsoldered bit. It's illegal per NASA and some MIL soldering standards.
These weird tools are used to control wicking
in some situations.
John
ferrules an a hand crimping tool can be found for a few bucks at Walmart. The solder makes the strands brittle and if there is some vibration the cable will break off. solder migration is not an issue here.
Ban
Just twist the wire first......strip bach 1/2" of insulation and leave it on the wire. Makes it easier to twist. Soldering will induce fractures with vibration.
Hi D! I think that if you're going to do the job, you are better off to do it right. That means follow the manufacturer's recommendations, when it comes to connectors of any kind.
BTW I think that many failures in electronic equipment are at the connection between one thing and another, whether it be solder connections, plugs that need reseating or other arrangement coming adrift through heat cycling, corrosion, electrolytic action, blah blah... always try to minimise such failures by making the best possible job of all electrical connections.
amark
D from BC wibbled on Monday 08 March 2010 03:08
2 problems:1) Solder "creeps" over time, so the screw that was tightened today may not remain tight.
2) IME, I have also observed, with finer wires, that the wire can break at the point between tinned and non tinned wire due to concentration of stresses.The right way is to crimp some "bootlace" uninsulated ferrules on the end, which is what I do with house wiring, if I'm terminating flex from say 12V downlighters (I use silicone HT flex for the last leg to these) into regular terminal blocks. Works very nicely. Don't buy the crimp tool from RS unless you like throwing money away - a little research on google and you can get decent ratchet tools for 20-30 quid. The ferrules are dirt cheap.
-- Tim Watts Managers, politicians and environmentalists: Nature's carbon buffer.
Silver solder is actually a braze, and as such you will have no insulation left on the wire after brazing it. It's made of similar metals as the wire, so it won't cold flow, not at this temperature anyway.
Tim
-- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
No, but "creep", in the metallurgical sense (slow deformation under stress), is. The solder filling the interstices between individual wires moves, allowing the connection to go slack.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
If you mean tin/lead/silver solder, the sort that you can use an iron with, that's as bad as ordinary tin/lead.
"Proper" silver solder, AKA hard solder, doesn't creep as much, but needs a brazing torch.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
The Europeans solder or crimp soft brass tubing onto the wire. Wire goes half in, screw clamps on the half without wire. I put brass tubing on large wire all the time. It really helps on the large wires, on "blind" terminal blocks that only grip about 1/4" of the wire. It will cold flow in about 10-15 years. The units I serviced had the mains wires (30 amp, 220, 3P) loosening up in 2005, they were made in
1985.Steve
On a sunny day (Sun, 7 Mar 2010 19:08:03 -0800) it happened D from BC wrote in :
Better not. It will get lose over time, and if there is a lot of current melt the terminal block. You need to uses these tubes (dunno the English worrd), and put those around the cable end.
----------- ----- metal tube |=======
----------- -----
Sometimes it is better to solder the cables in case of high currents,.
As others have mentioned, solder-tinning the ends is contra-indicated; the solder will cold flow or crumble and the connection loosen.
Either just use the bare (twisted) wire ends or (preferred) crimp a ferrule over the bundle. I use the ones from
For the crimper, if you have a compatible frame then you can get a set of dies pretty cheaply. If you need the whole setup, try a Lunar frame + die set p/n 300-001 at
-- Rich Webb Norfolk, VA
No.
The 'spring' in what you screw down on is what maintains pressure on the screw threads and so maintains friction to prevent the screw turning.
Compare the 'springiness' of a bit of solder with a similar bit of copper wire and why it is a bad idea is obvious (and the copper will work harden and become even more 'springy').
If you really don't want to use ferrules a dab of solder right on the end will hold the strands together while keeping just copper under the screw but it is hard to achieve consistently.
A friend used to (haven't seen him in decades so no idea if he ever "learned better" :>) part the strands into two groups. Then, slip the screw between the groups. Finally, twist the groups together on the "far side" of the screw. I.e., the screw is now captive to the wire.
This made it easy to attach wires in often hard to reach places -- but it was just *so* wrong in so many ways! :< (copper on the "right" side of the screw ends up being pushed out of the way as the screw is tightened)
[hmmm... that begs the question: what term to use to refer to describe the "side" (direction) that you turn *into*? E.g., what I have called "right" in this example]
The side into the wind would be "windward" side, so the other side would be "leeward". ;-)
wise *ss! :>
My question is serious: how do you refer to the "clockwise side" of something? etc.
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