Connecting threaded copper wire to solid hook wire

Thread Starter

quique123

Joined May 15, 2015
389
Yesterday I was trying to connect threaded copper wire, I believe 24 or 22AWG to small terminals in a relay board. I had the idea of making it easier by connecting the threaded copper wire to a small segment of solid hook wire which could then easily be introduced into the relay terminals. I would like to have your suggestions as to how best to accomplish this because these were my results and I did not really like the connections.

5A6D0A37-1D6F-4AB0-887A-1C2E2382044D.jpegF2A75C56-A50F-4D4F-87B8-269C367C0DCD.jpeg
 

jpanhalt

Joined Jan 18, 2008
8,460
Can you show the terminals you are trying to connect to? Are you using crimped fittings? If so, solid is worse that stranded for crimped fittings.
 

KeithWalker

Joined Jul 10, 2017
596
I have found in practice that the best way is as follows:
Strip the insulation on the multi-strand wire back about1/2".
Twist the strands firmly and evenly together with your fingers.
Thoroughly tin the wires using a soldering iron and rosin cored solder. Leaded solder is by far the best for this.
Trim the wire ends so that there is about 1/4" of bare wire.
Insert the wires in the terminal blocks and tighten the screws.
If the wire is too thick to insert in the terminal blocks, use thinner wire.
Regards,
Keith
 

Thread Starter

quique123

Joined May 15, 2015
389
Yes it did end up being to thick so I had to strip the insulation, cut half of the strands, then twist and then try to fit them in.

DE086053-B712-4713-B9DB-E49B1A79E1C9.jpeg

I liked the fact that with the hook wire there is less of a chance that wire from one terminal will accidentally come in contact with wire from its neighbor.
 

djsfantasi

Joined Apr 11, 2010
5,923
I have found that when the stranded wire is stripped, leave it on the wire. Separate the end insulation just barely. Then, twist the insulation as you pull it off the wire. This leaves the wire carefully and tightly twisted. Then, solder the twisted end and then closely wrap the solid wire around this core. One more application of solder and you should eventually get a neat transition. A bit of heat shrink, and you should have i solid connection.
 

jpanhalt

Joined Jan 18, 2008
8,460
A common and probably preferred way is to insert the stranded wire into a ferrule. Crimp it. Then insert the ferrule into that screw-compression connector. Lots for sources for suitable ferrules,including ordinary hardware stores.

Some examples:
https://www.mouser.com/datasheet/2/16/Ferrules8-9-1276430.pdf
https://www.weidmuller.com/bausteine.net/f/7862/Weidmuller_Ferrules_White_Paper.pdf

You may not even need to crimp, but that is the usual practice. The problem with solder on stranded wire is that it wicks into the wire and makes the wire more prone to being broken when it is flexed..
 

Wolframore

Joined Jan 21, 2019
1,530
Hehe reminds me of the NASA splice classes. Btw those screw terminals are good for up to 16ga wire. Just twist the ends and light tinning
 

MisterBill2

Joined Jan 23, 2018
4,847
Yes it did end up being to thick so I had to strip the insulation, cut half of the strands, then twist and then try to fit them in.

View attachment 196960

I liked the fact that with the hook wire there is less of a chance that wire from one terminal will accidentally come in contact with wire from its neighbor.
The terminal strip on the device in the picture should easily accept the stranded wire shown in the earlier pictures. BUT the first thing to do is back out the clamping screw on the terminal strip a bit, and then use a pointed object to push open the clamping strip a bit. After skinning the insulation back about 3/8 inch and twisting the strands a bit the wire will slide right into the terminal.
Over the years I have put several hundred wires into terminals like that, and most of the terminals do need to be opened a bit to get the wires in.
AND, the wire in the earlier pictures certainly looks larger than #24.
 
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