size of tails

[batty]

This has been discussed in great detail in a previous thread.

Batty

 

[mikel]

Thanks for your answers, I just wanted to make sure I hadn't missed anything, will bo quoting for new 25mm tails for both units. Think you all deserve a Guiness Drink for your help

 

[steptoe]

So Steps,Are you saying that when you change a CU, you leave the tails live??

Or do you get your DNO out to isolate?

Or has the seal fairy been? (In which case you are still not legally allowed to remove the main fuse)

EAWR comes to mind

I cannot condone breaking the law, use your own judgement...

COMPETENT I think is the word.......

 

[NozSpark]

I know what I, other people and probably yourself do (we do not work with live tails I am not getting into how I do this though)

What I was getting at was, as you'd have the power off to the tails then changing them is not going to add much cost.

 

[steptoe]

agreed, if you nhave priced the job to the fiver then perhaps your pricing structure is wrong.

YES,

for the sake of it, I also would bung in the 25mm tails.

 

[batty]

All depends what size consumer unit he is fitting. If it is a two way one then 16mm tails will easily be adequate. If it has more ways I would then fit 25 mm tails.

Batty

 

[binky]

25mm tails for 100A, 16mm tails fine up to 80A - check the big red book for single core wires (table at back)

100% of fuse carriers in my local area say 100A, but standard fuse is 80A or 60A - check meter, fuse is set to protect meter, old wheal type are rated at 80A, its written on the front (newer digital ones are rated at 100A, but fuses not upgraded at same time as changing to new meter anyway).

The 25mm bit is yet another stupid catch all recommendation and not a regulatory requirement. 16mm if fine, it will carry 80A and therefore fuse will blow before cable melts.

There is another argument that says if max current draw is eg 40A (separate cooker circuit or shower) then 6 or 10mm tails are fine 'cos they will never need to support 80A. But I think this is wrong, purely because of the lack of protection for the tails, even if it is very common on older installations.

 

[maccarooni]

So if a minor works is carried out and the cut out says 100A and the tails are 16mm. Does that mean the tails have to be Changed...?????

Or are we to presume or assume that there is a 80A or lower in the fuse carrier. This is the situation on a job i did today and was going to be one of my assessment jobs for nic. Now I'm totally confused...Also I have tried to find out by ENQUIRY from western power and got shoved from pillar to post an still never got an answer. Who exactly are we supposed to enquire from if the suppliers cant get me to the right department ???

Macca

Guiness DrinkGuiness DrinkGuiness Drink

 

[maccarooni]

Ok been on the phone for 37 mins.....6 different numbers and Finally got a definitive answer from western power metering in Bodmin. Quote " we would never put 100a fuse in cut out in a domestic property. Only up to a max of 80A but possibly only a 60A. The only way to verify whether 60 / 80A would be a site visit. Will that cost me I asked. Oh I don't know , Probably yes though".Unquote...... So when the Nic man asks me how I know the size of the main fuse, I can honestly say hand on heart, I enquired.......

MACCA

Now for a few of these

Guiness DrinkGuiness DrinkGuiness Drink

 

[binky]

Yep that's western powers' standard answer. Where abouts in pasty land are you then?

 

[ShockingExperience]

Not really, Mine is brand new and says 100 A on the front of it. But it is actull 80 A, because WPD are too tight to give out 100 A's.

Tut tut u been cutting the seals

 

[ShockingExperience]

I have been asked to quoe to replace a consumer unit with a new one. When I went to look at job I found that the flat has two consumer units fitted (wylex rewirable jobbies) one of which controls an economy 7 heating (storage heaters) and hot water immersion heater. the incoming supply is fed from a 100amp supply to a henley block where the tails are split to two different meters. From these meters tails go to each consumer unit. The 'normal unit' is fed by 25mm tails the economy 7 unit has 16mm tails. As i plan to renew the tails do I need to upgrade the tails to the economy 7 unit to 25mm. Hope this makes sense. I can't find anything in the 'wiring regs' but the on site guide says that meter tails should be 25 mm

In my views it matters NOT what is in the main fuse and sealed in place. If it says 100a YOU TAKE IT AT THAT. Its the way I was trained and the way we should think. 'assuming' its not 100a when it states it is is not a good idea.

You have to make provisions for what it 'could' be!

That is also how the NICEIC will view it. They know as much as you about what fuse link is sealed under there and will expect provision for what is actually stated on the cover.

 

[a1]

Not really, Mine is brand new and says 100 A on the front of it. But it is actull 80 A, because WPD are too tight to give out 100 A's.

Tut tut u been cutting the seals

Nope, I was the one that requested a higher Ampage. They came, told me it was too old to do and came back at a later date to redo it all. They put an 80 A in.

 

[maccarooni]

Yep that's western powers' standard answer. Where abouts in pasty land are you then?

hi binky, I'm in St Austell. Applaud Smiley

Are you down this way ?

Macca

 

[maccarooni]

In my views it matters NOT what is in the main fuse and sealed in place. If it says 100a YOU TAKE IT AT THAT. Its the way I was trained and the way we should think. 'assuming' its not 100a when it states it is is not a good idea.You have to make provisions for what it 'could' be!

That is also how the NICEIC will view it. They know as much as you about what fuse link is sealed under there and will expect provision for what is actually stated on the cover.

Hi shocking.

So even though i enquired and was told that they would never put a 100A in the cut out, am I then wrong for believing what they tell me ..? even though the labels all say RATED 100A. And the tails are 16mm and 10mm earth.

Macca

Guiness DrinkGuiness DrinkGuiness Drink

 

[kme]

Now then. Just to add to the fun here........

Metering & HED, in OUR area, has been passed from WPD to SWALEC. If I `phone them, they give me authority to cut the seals. :x

Then, when works complete, `phone back to tell `em, and they replace seals when next in the area....

Works for meGuiness Drink:x

 

[steptoe]

just as an aside,

when Im filling in my forms, whether 25mm tails or 16mm, I virtually always put down my main fuse as

UNVERIFIED

if I dont actually see it then I cant verify the size.

 

[Apache]

I'm no expert on these things but Steps is right. Unless you can physically see it (permission to cut seals) then you have to state it as unknown. You can't sign a certificate to the effect of a 100A fuse if there isn't one...........

 

[kme]

just as an aside,when Im filling in my forms, whether 25mm tails or 16mm, I virtually always put down my main fuse as

UNVERIFIED

if I dont actually see it then I cant verify the size.

100% concur.

 

[kme]

I'm no expert on these things but Steps is right. Unless you can physically see it (permission to cut seals) then you have to state it as unknown. You can't sign a certificate to the effect of a 100A fuse if there isn't one...........

Apache:

Doesn`t the size of the tail correlate directly to the size of the miniature horse? ?:|