25mm tails

[m4tty]

On a board change if you know the mainfuse is 60a and the property is quite small which you know would never pull anything near 60a. Would you use 16mm tails or just stick 25mm in. As it seems bait excessive to me.

Cheers

 

[Andy™]

usually 16mm

 

[Revved Up Sparky]

I would be inclined to phone the DNO first to make sure they have no plans to upgrade the cutout fuse, eg to 100A. With regard to the issue of loads, a future occupier of that property may decide to have a 10.6KW shower installed..... which could possibly call into question the adequacy of a 60A supply ?....

 

[ProDave]

Scottish Hydro fit 100A fuses as a matter of course now.

A recent rewire I did needed a cut out upgrade, and they replaced the 60A fuse with a 100A fuse in the new cut out.

I used 25mm tails on the CU and the DNO fitted new 25mm tails on their side as well.

 

[Theorysparky]

where i am they fit max of 80amp unless specifically asked for

 

[PC Electrics]

I wouldn't ring the DNO to ask - that might prompt them into coming round and changing it when you don't really need them to.

If someone "uprates" the installation at some later date, well that's their problem to deal with the larger tails issue.

As long as the fuse when you are there is 60 or 80A, then fit 16mm (hopefully they were 16mm in there anyway, so no cost of tails for you).

 

[m4tty]

Thanks for the replies everyone much appreciated. The 16mm tails there will be too short but I was thinking the same as you there pc.

 

[PC Electrics]

Thanks for the replies everyone much appreciated. The 16mm tails there will be too short but I was thinking the same as you there pc.

So just extend them then!

When I swap out 16s for 25s i keep hold of the good, reusable ones for just such an occasion. Don't throw out good copper that can be reused.

 

[Andy™]

So just extend them then!When I swap out 16s for 25s i keep hold of the good, reusable ones for just such an occasion. Don't throw out good copper that can be reused.

so im not the only one who has odd bits of 16/25 tails in the van

 

[PC Electrics]

[quote name='Andy

 

[Andy™]

nothing wrong with crimping earths & tails etc if there too short

obviously, if existing is half a metre and you need another 20cm, easier to replace. but sometimes (like you said above), its not always practical and easier to extend it

 

[sellers]

I have the mentality of the less joints the better. So I renew all tails when practically possible.

 

[Evans Electric]

I agree with PC,s comments where he says , assess the job as you see it at the time , therefore its 16mm tails . Exactly how I'd do it, we are not here to predict the future , " Perhaps a 10.5 kw shower may appear" " Perhaps the DNO will upgrade the main fuse" Well that becomes someone else,s problem IMHO.

As M4tty says, its a small house , probably max demand 30A ,"at the moment " and thats all you can assess unless you are told future plans.

I take Sellers point but again IMHO if it needs a joint , joint it , the whole system is held together by joints.

 

[Sidewinder]

I would always say it is better to replace than joint a bit on, however, correctly done joints are acceptable.

I just try to avoid them wherever possible.

I recently had to joint a 35mm sq SWA sub main, L, N, & E, no choice, other option was dig it up from under the patio, shed, and house to replace it, it was only about 6" too!

 

[fletchflash]

I have no problem with jointing bonding cable, but for some reason have that same mentality- would rather replace it.

I do have situations sometimes where i have to swap which side the main switch is in a new CU so old tails reach.

what do you use to crimp 16 or 25mm tails, uninsulated crimps and heatshrink? how do you double insulate?

 

[Sidewinder]

Tails are not double insulated anyway, so there is no need to double insulate any joints.

 

[sellers]

If the tails aren't in an enclosure or mechanical protection they should be double insulated.

 

[tom1]

insulated and sheathed not double insulated i think is what sidewinder is getting at

 

[sellers]

aye, its still double insulated to me, cables can't be exposed unless double isulated.

 

[fletchflash]

yeah meant insulated and sheathed. So you could heatshrink over the crimp but then would you need to further insulate if extended outside the CU?