Electrical items . . .

May 24, 2022 Last reply: 4 years ago 15 Replies

I'm just doing a bit of 12V wiring and came across these bits in my spares tin:



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The last 2 pics - a sort of clasped ferrule that appears to be crimped to the end of stranded wire. And a terminal block where the screw pushes down a plate, rather than relying on the screw to clamp the wire.



They both /look/ like good ideas to me, and I've not noticed a terminal block like this before. Any views on them, and a decent source/brand if used?


Good picture of a finger, but not of the terminal block. I have bought ones as you describe in the past, but couldn't point you at a source. IIRC, they are intended for stranded wire but are less successful on solid core wire.

Ha! I think you have to click the picture (in Apple's wisdom). I'll see if I can get it more in focus. Yes, they look better for stranded.

It's called 'wire protection' as far as the terminal block goes, I'd thought it was normal for all but the cheapest. It can be a bit fiddly if you want to re-use the terminal, as the leaf often needs to be bent back up with a small screwdriver or similar.

As for the ferrules or aglets, I wouldn't bother if I were using a wire protection terminal block, but would for a cheap screw clamp type.

Probably a reflection on the tat I end up working with! Wire pretection gets them up, thanks - on stock at RS for not very much more.

Another crimping tool though, and quite a range of prices.

Normal for DIN rail terminals in a control panel. They can be quite annoying when the flat strip comes adrift.

It happens that Clive Arthur formulated :

Boot lace furrules. They help with multi-stranded wire where it stops them splaying out when you try to insert them into a connector.

Is there a reason for using the furrules rather than just tinning the stranded wire. I tend to do this 'blob' with solder to stop the strands breaking and falling off when screwing in.

I'd avoid that if there were any chance of vibration, there's little flexibility left and the failure point will be where the tinning stops.

If you can manage to tin just the very end, then fairy nuff, but that's difficult to do.

The wire end things are usually called bootlace ferrules - fairly easy to get with the matching crimp tool:

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For the terminal blocks I would be tempted to use one of the Wago leaver terminal blocks since they work with stranded and solid core, and have cage style terminals.

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Solder tends to creep under screw pressure - so you tend to find connections slacken more rapidly over time.

Tinned ends tend to break due to fatigue at the tinned/untinned junction, ferrules are less likely to do the same because the junction isn't so abrupt.

whisky-dave was thinking very hard :

You should never ever tin the ends to clamp them, it is a really bad thing to do. The lead / tin under the clamping force gets pushed slowly to one side, leaving the screw offering no clamping force and poor, over heating termination.

Yes, I won't use any other. They are far better than the other type.

Bill

You have to poke it with a jeweller's screwdriver.

Bill

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