Has anyone experimented with screw-connections (ie those in accessories) vs. crimped?

As far as I'm concerned my crimp connections are OK.

Can't vouch for others.

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S George
http://www.state-it.com

I've never had a problem with crimped connections either.

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Yesterday I crimped a selection of 1.0, 1.5, 2.5 solid conductors using ordinary coloured "DIY" crimp lugs. I used my properly adjusted expensive German crimping tool. I tugged, pulled, twisted, wiggled, not one joint failed. I snapped a conductor or two through over enthusiastic wiggling and pulling in a vain attempt to get a failure, but the only failure on that note was me!

I must say, I don't think I've ever had to replace a burnt out lug either in domestic, commercial, industrial, even agricultural settings. We recently had some three phase motors with burnt out terminal blocks. All that was left in tact in ther terminal housing was the terminal studs and link bars (linked for star configuration if you're interested) and some nice yellow crimp lugs firmly crimped onto the SWA and bolted onto the studs.

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Regard
Richard (Dick)

www.rllewellyn.co.uk

Well Dick, you must have a good crimper there, is it just deforming the two sides of the crimp or is it closing it fully all round? It sounds as though its the all round type and giving good results! The coloured crimps (not DIY really) of good manufacture, with the correct tooling often do give satisfactory results on solid wires, but the manufacturers still do not recommend it. Regular testing of the crimp tool is vital. The matching of the tool and crimp is the only way to success, buying random crimps of unknown make is rarely satisfactory.

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David
CEng etc, don't ask, its a result not a question!

I've never had a problem with correctly made crimp joints on solid conductors. You are far more likely to see burnt up strip connectors than crimps in my experience !

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Empty barrels make the most noise.

hmm, singles up to 2.5 get the fold over treatment( and yes, properly done. We were always taught this, put into a crimp and using a DECENT crimp tool, never had a failure yet.

I'd like to see a 2.5mm doubled over using the correct size through crimp.

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Regards

Dave(not Cockburn)

Use a Wago

Andy

or cheap crimps.....

You can put a solid stranded cable in one side of the Wago and a solid in the other then waggle it about without worrying unless you are pulling on the cable as well, mind you there is a limit on available sizes.

Andy

Tyco make some good lugs called solistrand which are supposed to be very good. I'd like to try some, and then find somewhere I can buy a selection pack of them. Anybody any experience of these crimps?

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Regard
Richard (Dick)

www.rllewellyn.co.uk

I had some 30A junction boxes from Screwfix and they are dreadful, the base of the brass terminal is cast in lower than the plastic so the conductors do not sit down onto the brass when the screw is tightened down, also some of the slots were set in sideways making them unusable.

I not having any more of those.

Andy

Few years back had a short spell working for a company where my boss suggested I crimped connections for domestic wiring and ordered in crimps and a tool.

My experiments with this were worrying and I wasted quite a bit of time asking wholesalers for advice and then spent some time searching the web. In the end realised the crimp tool was not designed for insulated crimps. After getting new tool have not had problems with 1.0, 1.5 or 2.5 solid or 4 or 6mm stranded. Have used crimps and then heat shrinked sleeve over L and N with two layers of heat shrink overall to extend 2.5mm T&E.

But seeing the earlier postings now a bit worried again!

Yeah id have to agree there dg!

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Hi, looking for a new crimp tool - which particular expensive German variety are you using? Thanks!

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First off, why are you crimping. You do not need to crimp solid cable to terminate it into any type of connection block, mcb, din rail terminal ect.
If you are crimping to join cable then you should not crimp but do the job properly.
Crimps are for terminating stranded cable only and if you crimp solid conductors, under 16mm2, you are not doing your job properly.
If you are unsure, ask the cable manufacturer for advice not the crimp manufacturer.
ask yourself, could the cpc on a domestic 10kw shower carry the full fault current if it had a crimp fitting in place. How would do the calculations?.

And how might you suggest the job is done "properly"?

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Regard
Richard (Dick)

www.rllewellyn.co.uk

Although Im not a super sparks. I can remember when I was doing my CG2360 we were told not to crimp solid. And this was due to the crimp working loose.

How good is your solid crimp - I pass you over to the 'experts' for you to argue that one out:

4.3.4 Crimping. Stranded wire shall be used for crimping (Requirement). Crimping of solid wire is prohibited. Crimping of solder tinned wire is prohibited.

Source: NASA TECHNICAL STANDARD - NASA-STD 8739.4 - CRIMPING, INTERCONNECTING CABLES, HARNESSES, AND WIRING - page 23

8.5 Crimp Joints A finely stranded wire (large number of small diameter strands) usually improves crimped joint performance. A wire composed of a few strands of larger size will tend to act as a solid wire in the crimp. Some stranded wire crimp configurations are not satisfactory for solid wire. More deformation must be imposed in order to form wire and barrel into a solid mass. On the other hand, finer strands will more readily fill the inside corners of the crimp shape and more evenly distribute the forces of the crimp.

Source - Molex - INDUSTRIAL CRIMP QUALITY HANDBOOK - page 26

Conclusion - Draw your own

Regards

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E & OE

As i've said before I have no worries about crimping solid strand cables provided they can be left alone and not moved around too much after crimping, eg crimp as near to the enclosure as possible so not too much movement needed after crimping. I will say though I find crimping the old stranded 3/029-7/029 etc much more satisfying.
Having said all that, I have started to make more use of Helacon and Wago connectors recently,

Dave.