Tail size what do you use

[Griffin]

Hi All,

When changing a domestic CU, I normally replace / upgrade to 25mm tails regardless of the main fuse size.

What do you guys do???, I was talking to a colleague who sticks with 16mm on a 60amp.

Answers on a postcard!!!

G

 

[robsparx]

16mm on a 60amp is fine, but i just use 25mm every time when changing a CU

 

[baldsparkies]

Depends on the max demand of the install in general, to be fair considering the average length of the tails ie less than 3 mtrs (a lot less in most cases) chances are your not going to have much of an issue.
If you like to use 25mm tails so be it, but 16mm is often good enough.
That said I use 25mm if upgrading.

 

[allsparkjonny]

i tend to use 25mm regardless of fuse size

 

[marksparky]

we still would use 16mm tails on domestic up to 80a 1mtr in length

 

[dufjax]

I use 25mm got a job lot that appeared in my van


Jim

 

[Darkwood]

If the cutout is rated up to 100amps then 25mm to be used as its possible the fuses may be changed at some point.

 

[flukey]

16mm fine if 60 amp in place

if someone comes along later and changes fuse to 100 amp its down to them to change the tails too

 

[Darkwood]

16mm fine if 60 amp in place

if someone comes along later and changes fuse to 100 amp its down to them to change the tails too

I agree but the DNO are their own entity and they tend not to bother checking tail size when replacing fuses or upgrading cutouts as its on customers side all they bother with is earthing is done. Also the fuse type they fit allows for long duration on smaller overloads but this can exceed the tails tolerances if say 16mm fitted. I would only fit smaller tails if the load downstream is limited by the nature of the mcb's fitted like a 1 or 2 way board with max load of the mcb's cant exceed the cables capacity without the mcb's tripping themselves.

 

[Phil]

25mm I just get the pack with the earthing and tails kit

 

[dufjax]

25mm I just get the pack with the earthing and tails kit

Seen them the look a good buy. (If you don't get a 100% discount on 25mm like a certain someone)

They also sell them in B&Q so even good idea for the "Excellent time to upgrade your consumer unit" diyers


Jim

 

[Phil]

think i pay about £4.50 plus vat in the wholesalers for the kit. used to have them cut off the reel but got fed up waiting for an hour while the guy wandered off, probably had a cig and a couple of coffees whilst he had us stood there waiting

 

[GaryM]

We normally buy 10M at at time of 25mm L&N and 16mm earth.
It cuts down a little on wastage.

 

[flukey]

I would only fit smaller tails if the load downstream is limited by the nature of the mcb's fitted like a 1 or 2 way board with max load of the mcb's cant exceed the cables capacity without the mcb's tripping themselves.

the op is about a cu chage with existing 16mm tails on a 60 amp fuse

in answer to his question there is no need to upgrade to 25mm as the ccc is fine

if the customer is having extra circuits put in at the same time and it is likely the fuse will be upgraded then put 25`s in

have yet to find a dno that will put a 100 amp fuse in with 16mm tails in place

 

[Griffin]

Thanks for your thoughts and opinions.

Regards

G