upgrade meter tails, or downgrade main incoming fuse??

[Knobhead]

all my customers appreciate my good quality work,knowledge and professionalism so my advice is golden to them its not much of a hassle to have this done actually can benifit in future , they are there for a reason thats why every new build will have L in and out of switch and nuetral in & out

Which planet are you on?

 

[MDJ]

:26: ah yes friday night again.

 

[Engineer54]

You only NEED 25mm tails is if there is a 100A cut out fuse. Otherwise 16mm will be fine!! It may be prudent to realise that a 100A cut out fuse can only be provided when the Ze/Zs available is adequate to provide clearance times....

I have yet to see a typical standard to large domestic installation come anywhere near drawing a 100A or anything close to it!! Far too many here take more notice of a guidance drawing in the OSG, than using their training and commonsense!!

 

[SLSpark]

Which planet are you on?

What u getting at ?
Customers don't call electricians in because they know what there talking about
Tony

 

[malcolmsanford]

Hold onto your snips martin,
The requirement for 25mm tails are part of the PME supply regulations so if the supply is PME there is no getting away from that

hmmmm.................................

 

[Knobhead]

:s every new property has this as standard so copper prices are not the issue , the guys asked for advice put in 25mm and allow for growth of the electrical system

Planet Spongle I think.

What groth of the electrical system, it's a house for gods sake!

 

[SLSpark]

Planet Spongle I think.

What groth of the electrical system, it's a house for gods sake!

Yes a house with no electric shower electric cooker ,pv system outbuilding supplys etc etc etc.

if the fuse is sealed and there is local isolation how do you know what size the fuse is ,only indication it the 100a sticker on cable head fuse.

still cant see the big fuss about fitting 25mm tails while changing a DB

:s

 

[SYKRAPS]

Its the weekend, everyone should be smiling and playing nicely

 

[imago]

Regulations, guidance notes, DNO requirements, actual demand figures, and fuse sizes. To be honest the main reason I upgrade to 25mm tails is for an easy/quiet life.

I could demonstrate by readings and/or calculations that 16mm would be more than adequate. The thing is though, it's easier, cheaper, and quicker just to swap the tails out, so I do. The same goes for 10mm to 16mm main earth and 6mm to 10mm bonding in a lot of cases too.

 

[SLSpark]

Regulations, guidance notes, DNO requirements, actual demand figures, and fuse sizes. To be honest the main reason I upgrade to 25mm tails is for an easy/quiet life.

I could demonstrate by readings and/or calculations that 16mm would be more than adequate. The thing is though, it's easier, cheaper, and quicker just to swap the tails out, so I do. The same goes for 10mm to 16mm main earth and 6mm to 10mm bonding in a lot of cases too.

my point exactly ,i also upgrade the main earth to 16mm,
no ones said 16mm mains tails isnt adequate but good practice to upgrade while changing DB.

 

[GLENNSPARK]

Planet Spongle I think.

What groth of the electrical system, it's a house for gods sake!

i think he might mean growers tony.....

 

[Engineer54]

Regulations, guidance notes, DNO requirements, actual demand figures, and fuse sizes. To be honest the main reason I upgrade to 25mm tails is for an easy/quiet life.

I could demonstrate by readings and/or calculations that 16mm would be more than adequate. The thing is though, it's easier, cheaper, and quicker just to swap the tails out, so I do. The same goes for 10mm to 16mm main earth and 6mm to 10mm bonding in a lot of cases too.

What's easy about dressing and connecting 25mm tails into tight CU enclosures, when in most circumstances isn't actually required anyway?? I maybe missing something here, but how is it ''easier, quicker and cheaper'' to swap out, the existing correctly sized tails for unnecessary 25mm tails??

 

[SLSpark]

What's easy about dressing and connecting 25mm tails into tight CU enclosures, when in most circumstances isn't actually required anyway?? I maybe missing something here, but how is it ''easier, quicker and cheaper'' to swap out, the existing correctly sized tails for unnecessary 25mm tails??

I personally don't find it a challenge to connect 25mm tails into any db I have fitted terminals are more than adequately sized and easy enough to "dress" the 3 meters max of cable

 

[imago]

What's easy about dressing and connecting 25mm tails into tight CU enclosures, when in most circumstances isn't actually required anyway?? I maybe missing something here, but how is it ''easier, quicker and cheaper'' to swap out, the existing correctly sized tails for unnecessary 25mm tails??

They're not too bad to do into a Hager board which is what I use 99% of the time, but I take your point. A 'typical' CU change for me will be on a three bed house built from the '30s to the '70s. A lot of them will have vastly increased loads from the original or even the rewired in the '70s or '80s installation. You are quite right that they're still nowhere near the 100 or even 80 amp draw though. I find customers fall into two categories mostly: 1) Don't care what you need to do, just get on with it. and 2) Read up a bit, or had another 'electrician' in to quote. The larger group is 2). So for me to take time explaining why the 'advice' they've found on the internet, or the "You've got to upgrade the tails." statement by previous sparks isn't necessarily the case takes too long for the additional few quid difference in replacing the tails. If you vary too far from the majority 'opinion' in a lot of cases it can give the impression you're cutting corners.

 

[Engineer54]

I personally don't find it a challenge to connect 25mm tails into any db I have fitted terminals are more than adequately sized and easy enough to "dress" the 3 meters max of cable

Just not necessary in the majority of cases!!

I was talking about within the CU, not outside of it. Wasn't saying that terminals weren't adequately sized either. But your not telling me that 25mm tails in a CU, aren't more of a challenge to dress than 16mm. Most UK CU's, don't give you much room for any wiring, some are a real challenge space wise, to fit RCBOS . ..lol!!!

 

[Knobhead]

i think he might mean growers tony.....


View attachment 15772

Special regulations apply there Glenn, you need the 17[SUP]th[/SUP] edition of the Hydroponics Wiring Regulations.

 

[danf1966]

OSG .....2.2.3 minimum tail csa should be 25mm

 

[imago]

OSG .....2.2.3 minimum tail csa should be 25mm

OSG On Site Guide

 

[GLENNSPARK]

OSG .....2.2.3 minimum tail csa should be 25mm

aye and it also shows a nice diagram of a TT system with 16mm CSA main earthing....lol....

 

[GLENNSPARK]

Special regulations apply there Glenn, you need the 17[SUP]th[/SUP] edition of the Hydroponics Wiring Regulations.

the `happy funny farm` eh...lol...:rolleyes4: