Joining Copper Cable

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Help - need to find a supplier of the "Tube" style joiners for thick copper cable

The cable core is 12mm dia (excl insulation) - I need to join 2 lengths together - trying to find a supplier for such thick cable is proving difficult

Suggestions gratefuly received

Cheers
rob
 
An easy and I feel satisfactory solution to join large diameter cables, is to use short lengths of copper water pipe. The pipe is available in many diameters. Match the inside diameter of the pipe with the outside diameter of the wire conductors. It should be a tight fit. Clean the inside of the pipe then push the conductors in each end. Crimp the copper pipe around the wire for mechanical strength then solder ( you need a very big soldering iron ) for electrical conductivity. Wrap in a couple of layers of glue lined heat srink and preferably some conduit.
It produces a low resistance, waterproof, mechanically strong, cheap and neat join that is not much larger than the existing wire. It is a less flexible over the join so support it if there is any vibration / movement.
 
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vyv_cox said:
I think you will find it is double that. PiR2 is 6 x 6 x 3.142, which in my head is over 100 mm2
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Can't argue with the sums but, I bought some 95mm2 cable recently, and it measures about 12mm diameter. With the insulation, it measures about 23mm diameter!!

95mm2 crimps slide on tightly, so pretty sure it's 95mm2 as described.
 
robmchugh said:
Help - need to find a supplier of the "Tube" style joiners for thick copper cable

The cable core is 12mm dia (excl insulation) - I need to join 2 lengths together - trying to find a supplier for such thick cable is proving difficult

Suggestions gratefuly received
Click to expand...

Sounds like you have 95mm2 cable. You can get tube connectors for this size, but they're usually sold in packs of 50 or 100. It's possible you might be able to get a smaller quantity from a supplier if you ask nicely! Google for "Elpress KSF95" - this is a copper crimp connector for 95mm2 cable; because it's designed for crimping, the internal diameter is actually 15mm. It obviously needs a professional crimping tool. If you were intending soldering instead (quite feasible with a gas blowlamp), you might look at the KSF70 connector, which has 13mm internal diameter. If you're going to heat with a blowlamp, wrapping wet kitchen paper around the insulation at the ends of the cables will help minimise melting damage. It's a good idea to slide some glue-filled heatshrink over the cable first, so you can cover/insulate the joint afterwards.

Elpress-Copper-Tube-Cu-Through-Connectors-KST.jpg
 
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robmchugh said:
Help - need to find a supplier of the "Tube" style joiners for thick copper cable

The cable core is 12mm dia (excl insulation) - I need to join 2 lengths together - trying to find a supplier for such thick cable is proving difficult

Suggestions gratefuly received

Cheers
rob
Click to expand...

An electrical wholesaler (or an electrician) could supply a clamp connector for that diameter, which would be my own preferrence.
 
For anyone doing this here have been my experiences.
To make a proper crimp that is mechanically and electrically strong you need a very good hydraulic crimper these almost fuse the wire to the connecter. The sort of crimpers that most amateurs or even marine professionals use is not as good.
So I prefer to crimp then solder. The crimp can be done in a vise with some suitable dies and a long extension handle. Some use the hammer crimpers. Some use marine SS standing rigging swage tools. This will form a good mechanical conection test by seeing if you can pull it appart, but I do not feel it provides a good electrical conection, so I solder it as well. The two methods work well and compliment each other, the solder helps the mechanical stentgth, but does make the joint and the wire a bit more brittle. It is also more time consuming, but feasible for the amateur.
To solder try a and use a large soldering iron if you can. A blowtorch works, but is difficult to control the heat. 100- 150 w soldering irons can be purchased quite cheaply. They a crude with no temperature control, but better than a blowtorch in terms of heat control. Sometimes more than one iron is a help heating up the same joint.
Around 95 mm2 wire can be done this way.
Get glue lined heatshrink it is much better for marine connections. Use at least a couple layers and stagger the length.
 
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I don't consider soldering a good option, especially for larger cable sizes where movement of the cable will put high stress on the outer strands at the solder interface.
 
savageseadog said:
I don't consider soldering a good option, especially for larger cable sizes where movement of the cable will put high stress on the outer strands at the solder interface.
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Movement also puts stress on crimped joints. With adequate cable support, soldering is fine in the context of a leisure boat.
 
noelex said:
An easy and I feel satisfactory solution to join large diameter cables, is to use short lengths of copper water pipe. The pipe is available in many diameters. Match the inside diameter of the pipe with the outside diameter of the wire conductors. It should be a tight fit. Clean the inside of the pipe then push the conductors in each end. Crimp the copper pipe around the wire for mechanical strength then solder ( you need a very big soldering iron ) for electrical conductivity. Wrap in a couple of layers of glue lined heat srink and preferably some conduit.
It produces a low resistance, waterproof, mechanically strong, cheap and neat join that is not much larger than the existing wire. It is a less flexible over the join so support it if there is any vibration / movement.
Click to expand...

Yup. I have used this method but after cleaning the inside of the copper tube I "tin" it and have always used a blowlamp.
clean the tube inside, apply flux, then heat and apply a thin layer of solder all around the inside of the tube.
do the same with the ends of the cable by fluxing and with the bare end of the cable pointing up heat and then apply a few dabs of solder to the cable allowing the solder to run down between the strands.
then fit cable into the tube with a little more flux crimp in a vice or similar and then heat and solder the whole lot.
 
robmchugh said:
Help - need to find a supplier of the "Tube" style joiners for thick copper cable

The cable core is 12mm dia (excl insulation) - I need to join 2 lengths together - trying to find a supplier for such thick cable is proving difficult

Suggestions gratefuly received

Cheers
rob
Click to expand...

http://www.ebay.co.uk/itm/Butt-spli...CarParts_SM&hash=item5892d61888#ht_2095wt_735

I bought the lugs, heatshrink and 95mm2 cable on eBay. Couldn't find any of it to buy in a shop I could drive to and walk into.
 
saltylegs said:
Yup. I have used this method but after cleaning the inside of the copper tube I "tin" it and have always used a blowlamp.
clean the tube inside, apply flux, then heat and apply a thin layer of solder all around the inside of the tube.
do the same with the ends of the cable by fluxing and with the bare end of the cable pointing up heat and then apply a few dabs of solder to the cable allowing the solder to run down between the strands.
then fit cable into the tube with a little more flux crimp in a vice or similar and then heat and solder the whole lot.
Click to expand...

The only thing I'd add to that is to drill a hole in the pipe halfway along so you can see the cables butting and also dump some solder in it. To do the job properly a blowtorch for the copper that you can keep on it handsfree whilst using a very large iron on the cable is a bonus. The iron I used to use for this sort of thing was an old plumbers iron which was heated in a blowtorch flame.
 
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