25mm in-line crimps

[Chris Electron]

Hello,

For the first time I need to use some 25mm uninsulated crimps. These connections are going into a junction box. My plan is to put heat shrink over them to insulate.

Is heat shrink ok to do this job? Also what current rating are these crimps? Anything else I should be looking out for? (tried to google info but can't find much)

Many thanks,

Chris.

 

[uksparks]

I would imagine the crimps are suitable for the size cable you put in them, with that size cable it's likely you will be drawing a fair current so make sure you use good quality crimps and a good ratchet crumpet as you don't want a poor connection.

As for covering them, I would use 20mm 4:1 Heatshrinkonline tubing and probably put two layers on it.

 

[Marvo]

As per UKsparks comments although we don't have a ratchet crumpet We also have a very thick heatshrink we often use for this but you can put 2 x layers of normal heatshrink on each ferrule.

 

[Rockingit]

But is heatshrink actually tested and rated as an insulator? If so, surely it would need a VDE / dielectric style rating? Not sure.

Also, why would the OP need to use in-line crimps going into a JB? Lugs, maybe? Something not quite adding up here!

 

[Octopus]

OK, I'll ask the obvious question!

Why are you extending 25mm cables????

 

[Marvo]

Yeah, I've no idea what he's trying to achieve but you can get 25mm din-mounted terminals or even line-tap connectors with insulated covers. Also if it's a single cable in and out maybe a resin joint.

 

[Chris Electron]

Armoured sub main. Where consumer unit is going to be mounted I cannot terminate the armoured directly into the board. Therefore am mounting a large jb behind where board will mounted. Then running 25mm tails into board.
Was going to have a Henley block but client plans changed making it very hard to access. Therefore needed to crimp.

 

[uksparks]

Sorry, was on iPad and it keeps changing what I type as you probably frequently notice e.g. the ratchet crumpet

 

[uksparks]

I am not a fan of crimping big cables like 25mm as I feel its just not the same as a continuous piece, 16mm I will crimp, but 25mm I just get a little uneasy about it.

Rockingit, you have a good point about the rating of the heat shrink.

 

[telectrix]

why not fit a 6" x 4" adaptable box with henleys inside it?

 

[wozz]

Ive always found ratchet crimpers for this size are crap and are usually indent, i prefer the non ratchet ones that are hexagonal. less parts to go wrong on them and feel sturdier.

 

[Knobhead]

So why cut the cores and extend them? Heat shrink the cores and take them to where needed. Remember the outer sheath of tails is not classed as insulation.

I can’t see any sense in putting through crimps where they’re not needed.

 

[Eddiesparks]

Just twist them together and use a bit of red tape on them. Standard

 

[telectrix]

brown tape now.

 

[Plonker 3]

No red tape, brown tape would show it was a notifiable job under Part P

 

[shanky887614]

No red tape, brown tape would show it was a notifiable job under Part P

Only works if using old stock.

Would look odd on new colours with br, blu, g+y

Or

Brown, black and gray

 

[Plonker 3]

Just use black singles

 

[Engineer54]

I am not a fan of crimping big cables like 25mm as I feel its just not the same as a continuous piece, 16mm I will crimp, but 25mm I just get a little uneasy about it.

Rockingit, you have a good point about the rating of the heat shrink.

God help anyone that needs to through crimp anything from 25mm to say 400/600mm then...lol!!

Crimp ferrules are rated the same CCC or higher, than the conductor they are designed/manufactured to accommodate... I've seen conductors stretch, way before a crimped connection will fail...

All LV insulation heat shrink tubing i've ever come across has had minimum XLPE insulation rating 600/1000V. To the best of my knowledge, there is no such thing as PVC heat shrink. Even the heatshrink cable sheathing with internal adhesive is of XLPE in construction...

 

[HandySparks]

To the best of my knowledge, there is no such thing as PVC heat shrink. Even the heatshrink cable sheathing with internal adhesive is of XLPE in construction...

I suspect that the most widely used heatshrink type is polyolefin.

However, pvc is available:
PVC Heat Shrink Tubing from Allied Wire and Cable Distributor of Heat Shrinkable Tubing, Sleeving

As are many other materials:
Heat Shrink Tubing (M23053) from Allied Wire & Cable | Distributor of Tubing, Sleeving & Spiral Wrap

Do you have a link to XLPE heatshrink (not just heatshrink for use with XLPE cables)?

 

[Geordie Spark]

Sorry, was on iPad and it keeps changing what I type as you probably frequently notice e.g. the ratchet crumpet

Aye .... it's been a good few years since I sampled the delights of a bit or ratchet crumpet,