What's the Best Way to Connect a 4mm Wire to the Middle of a 6mm Wire?

[mischief]

Okay so I'm ready to start making my terminations on my new wiring. I'm using a combination of 4mm and 6mm wire. The 6mm wire runs like a backbone for lights then the 4mm runs to the light location. I'm comfortable In the wire selection etc so please let's just stick with the termination aspect.

So what's the best way to terminate 3 wires together. Ie 2x6mm plus 1x4mm?
Originally they stripped back part of one wire and then wrapped the other and soldiered it. I had planned to use a connector with a grub screw and diode electric grease plus fully sealing it. But I'm worried the grub screw will break some of the strands of wire. So then I'm thinking what about some copper tub crimped over a group twist of all 3? There's got to be a proper way.
What are people's thoughts?
Cheers

[Tim R.]

I would use a terminal block with a jumper.

[sailvayu]

Here in the US the only type of connection approved is a crimp connection. You can get a crimp connector that looks like a wire nut but is crimped closed, I forget what they are called but any place you get crimp connectors will have them. As Tim said terminal blocks are good as well but the same applies to using crimp connectors to the terminal block.

[GordMay]

Originally Posted by sailvayu

... You can get a crimp connector that looks like a wire nut but is crimped closed ...

Buchanan Splice Cap Crimp Connectors

➥ Splice Cap Crimp Terminal (Box of 100)

➥ Ideal Industries - Buchanan Pre-insulated Crimp Connectors

If you wish to tap onto an unbroken run of wire, use a split bolt ➥ http://www.ilsco.com/productcategory...eC1yutRA%3D%3D

[mischief]

Thanks, I've been to every wiring place around here in Australia when I was trying to figure this out. But nobody had anything like that and when I had asked about this scenario they stared off into space. Those are basically what I'm after. The split bolts look good too but I wonder if they would fit into the 20mm space they would have to. I had thought of terminal blocks too or rather eye connections combined with a copper nut and bolt. Out of all the options here I wonder which would have the least resistance? I'm thinking a proper crimp. Now if I cannot locate these types of crimps or split bolts what about just using some copper tubing to crimp? Thoughts?

[sailvayu]

Its a bit ethnic but if it is all you have I think it would work. Use a small diameter tube, crimp with a proper crimping tool (that has a lot to do with it) and heat shrink over it. You are talking low amp lights so should not be too bad. Personally I would rather see that than a split bolt those things are not worth a crap and loosen up all the time. Same for ring terminals with a bolt that is just too ethnic for me! Gotta love the blank look from the parts guys when you ask for something they know nothing about lol.

[mischief]

Btw sorry for the spelling etc. I can't seem to edit and half the time I can't see what I'm typing. I think I'll have to reinstall my cruiser ap.
cheers

[cszosler]

Hi,
What I'm doing is not professional but works well. I do make "junction box" out of old camera film containers (black). Make as many holes as many wires to connect, each is smaller than each wire. all wires are then tighten inside dual screw connectors. then container body cover all junction. Doing this I've got water prof, easy accessible for testing and modification junction box. It may not physically fit or affect viewing pleasure, but wires may be altered to suitable place. This is what I do.

[goboatingnow]

One of the proper ways is to use crimped ring terminals and a terminal block inside a waterproof junction boc with appreciate glands , everything else is a lash up. For good practice look at the loom in your car. Those crimp connectors provide poor moisture resistance , little mechanical support and have the potential for failure. They are be step up from wire nuts, which quite frankly are an abomination.

Also if using screw terminals try and crimp on the appropriate ferrule rather then ever tightening down on multi strand wire directly

There are other forms of interconnect as well , have a perusal of the Mouser catalogue or farnell components. Since your labour is free, invest in high quality connectors , ( and not bits of copper tubing )

Dave

[Ian R]

Be aware 6mm cable from whitworths and others in australia is really 4.59 square mm. Read the fine print on the cable drum. If the cable came from an electrical wholesaler it will be in square mm. I don't know where the 6mm etc BS comes from.

[mischief]

Well I'll be, I just checked the drum and it says 6mm td marine then it says 4.59mm square.
Okay well I'm mostly led and energy efficient fans so I'm way overkill on my wiring but I did it this way to maximize longevity and have plenty of room for resistance etc. it's a good thing I wasn't maxing out the wire based on 6mm. Sheesh.
I'm still hunting for more correct connects in Australia but no luck yet.
I agree with not wanting to screw down a screw against the fine strand. Btw that's the point I got to before when trying to find terminals. I bought a box of twin screw brass connectors I planned to use diode grease and seal with electrical epoxy potting mix. But then had a change of heart as I'm not comfortable screwing the screws to the fine strand.
On another note I have read all mainsails blog and agree with his methodology however he does not cover this type of connection, well at least that I've found.
I do know many have had success using copper tubing for making custom battery lugs and that's where I was getting the idea.
Again I only have 20mm free clearance above my headliner. I really need to use something that is low profile.
I can see why they originally twisted the wires and soldiered. In all fairness the connections were still good after 26 years and the failed ones were at terminal boxes. If corse the terminal boxes happened to be more exposed to moisture.

[BillAU]

Originally Posted by mischief

I'm still hunting for more correct connects in Australia but no luck yet.

G'day mischief, I believe this is what you're looking for, I was looking for the same items, found them on eBay.com.au after finding the correct name for them, but at $40.76 for five, that's $8.152 each, (includes postage from the USA) I think I'll go with the copper tube idea

Originally Posted by mischief

I do know many have had success using copper tubing for making custom battery lugs and that's where I was getting the idea.
Again I only have 20mm free clearance above my headliner. I really need to use something that is low profile.
I can see why they originally twisted the wires and soldiered. In all fairness the connections were still good after 26 years and the failed ones were at terminal boxes. If corse the terminal boxes happened to be more exposed to moisture.

Use a good crimping tool when crimping the copper pipe, heatshrink and tape the joint and it should last a lifetime

Bill
Australia