Why oh why 25mm meter tails?

[sparc]

Does anyone understand the logic of 'mandating' 25mm meter tails when upgrading a CU, when the sizing of other cables are left to the electrician's discretion?

I'm again having to explain to a little old lady with not a lot of money that she's need new meter tails with with tiny 6-way board, for her tiny 2-bedroom flat.

Massively cooking range to feed? Nope! 10.8Kw Powershower? Nooooh!

When copper is becoming an increasingly rare resource shouldn't we be fitting what's needed?

My guess is that the IET are simply 10 years out of date, plus someone somewhere calculate the specification, then a sub committee adds 10% to that, and the main committee thinks - let's be in the safe side, and adds another 10%.

Craziness gone mad!!!

(Rant for the day over - thank you for listening)

 

[UNG]

Where the tails run from meter to CU/DB is not normally sealed, just a removable cover plate.

with a seal on it lol

if meter is sealed and tails need changing this is where mr henley comes in

Some meters have a split terminal cover on the consumers side that is not sealed and has an isolator behind the cover so you can work dead occasionally some DNO's fit an isolator after the meter which has a split cover arrangement allowing access to the consumers side terminals only

Ok, I know that, what I was trying to say was perhaps I could assume that the distributor's requirement for the csa of the tails on the consumers side of the meter would not exceed the csa of their own tails on their side of the meter, I just didn't explain myself very well. I'm guessing that the main fuse is probably only a 60A or 80A but I haven't checked yet.

Why do I feel like I am digging myself into a hole

Years ago when you got the electricity board to connect tails after a rewire they would expect you to install 16 or 25mm² tails but the tails from the cut out to the meter where usually well undersized

I rewired my house recently - in fact, truth to tell, it's still ongoing - but I fitted 25mm tails from the new 15 way main switch + RCBO'd board to my isolator.

From the isolator back to the meter, & from the meter back to the cut out, the tails are the "old coloured" 16mm. Then the bloke came to change the meter not asked for by me, but sent by DNO and I handed him a nice new pair of tails & asked him to fit them in place of the old 16mm pair.

He refused, claiming it wasn't his job, so I now have what I think is the ludicrous situation of having 16mm "old coloured" tails from the cut out as far as the isolator, & then 25mm tails from the isolator to the CU.

The mind boggles !!!!

Last few meter changes I have seen done they changed the tails on the DNO side to 25mm² in the new colours

Yeah, I think they just wanted to stop curious people from removing the lid and killing themselves, I thought that it was a bit strange, nothing to do with them really.

Years ago the old electricity boards always sealed the henley blocks

 

[flukey]

Some meters have a split terminal cover on the consumers side that is not sealed and has an isolator behind the cover so you can work dead occasionally some DNO's fit an isolator after the meter which has a split cover arrangement allowing access to the consumers side terminals only

i have yet to come across a meter with an unsealed cover but sounds like a bloody good idea.


if isolators were fitted as standard then this thread wouldnt exist.

truth is, not many dno fit them so the choice is either install your own with 25mm tails on consumers side or henley them

 

[sparc]

with a seal on it lol

if meter is sealed and tails need changing this is where mr henley comes in

If the meter is sealed and the tails need changing then how does a henley block help? If there's one already installed between meter and CU, certainly. If not, you're going to have to open the meter to release the tails.

 

[flukey]

If the meter is sealed and the tails need changing then how does a henley block help? If there's one already installed between meter and CU, certainly. If not, you're going to have to open the meter to release the tails.

put meter tails into henley or isolator then into cu :dizzy2:

im all for cutting cutout seals but meter seals is a big no no

 

[1shortcircuit]

put meter tails into henley or isolator then into cu :dizzy2:

im all for cutting cutout seals but meter seals is a big no no

1 seal = Meter tail teminations other seal = ??? There's a reason I don't know the answer to the second. The reason I know the first is only because I read it on a public forum somewhere :thumbsup

 

[flukey]

1 seal = Meter tail teminations other seal = ??? There's a reason I don't know the answer to the second. The reason I know the first is only because I read it on a public forum somewhere :thumbsup

thats it youve lost me????????

 

[sparc]

put meter tails into henley or isolator then into cu :dizzy2:

im all for cutting cutout seals but meter seals is a big no no

Have to disagree with you there, flukey, or maybe I'm just not understanding you.

If this is about upgrading existing 16mm2 tails coming from the meter into CU then putting a Henley block in there isn't going to make them 25mm2 - You'll just have 16mm to service block, then 25mm from there to the CU. I don't think that's what the regs mean!

 

[jase]

yes sparc, but what flukey is doing by having 16mm out of meter to service block and then service block to CU in 25mm is leaving it so that the DNO can take the 25mm's straight into meter at a later date

 

[Edd]

I rewired my house recently - in fact, truth to tell, it's still ongoing - but I fitted 25mm tails from the new 15 way main switch + RCBO'd board to my isolator.

From the isolator back to the meter, & from the meter back to the cut out, the tails are the "old coloured" 16mm. Then the bloke came to change the meter not asked for by me, but sent by DNO and I handed him a nice new pair of tails & asked him to fit them in place of the old 16mm pair.

He refused, claiming it wasn't his job, so I now have what I think is the ludicrous situation of having 16mm "old coloured" tails from the cut out as far as the isolator, & then 25mm tails from the isolator to the CU.

The mind boggles !!!!

I think he may have been telling porky's, when I did a year of meter changing for the EEB (as it was at the time) we were told and given rolls of 25mm and Henley blocks and had to up the tails to 25mm if smaller was found... truth be told we were on price and I have to admit it we were changing them in minuits and the last thing we needed was to upgrade the tails!! maybe the DNO's policy has changed but we didnt change them not because it wasnt our job, but because we couldnt be bothered!!!



EDIT to say this was 20 years ago!! my morels have changed!

 

[1shortcircuit]

thats it youve lost me????????

Main cut out to meter and meter to consumer unit. Two seals on the meter one of which gives access to where the tails get terminated. The other seal I'm guessing gives you acces to the internals of the meter itself. I've never opened the other seals but Yes (Tin hat on) I have opened the seal to be able to terminate new 25mm tails from cut out to meter, meter to CU. If you leave 16mm before any 25mm tails then what's the point in altering anything?

 

[flukey]

Have to disagree with you there, flukey, or maybe I'm just not understanding you.

If this is about upgrading existing 16mm2 tails coming from the meter into CU then putting a Henley block in there isn't going to make them 25mm2 - You'll just have 16mm to service block, then 25mm from there to the CU. I don't think that's what the regs mean!

no problem with a bit of disagreement

YOU cant put 25mm tails into meter, but meter man can next time he comes

 

[sparc]

yes sparc, but what flukey is doing by having 16mm out of meter to service block and then service block to CU in 25mm is leaving it so that the DNO can take the 25mm's straight into meter at a later date

Thanks for clarifying, but it seems a pointless exercise if you ask me. I regard the meter tails as starting at the meter and ending at the distribution board. Electrically, having a bit of 25mm2 for the last segment doesn't change the overalll current carrying capacity of the tails, which are still limited to 87A by the 16mm segments. - IMHO.

 

[flukey]

Main cut out to meter and meter to consumer unit. Two seals on the meter one of which gives access to where the tails get terminated. The other seal I'm guessing gives you acces to the internals of the meter itself. I've never opened the other seals but Yes (Tin hat on) I have opened the seal to be able to terminate new 25mm tails from cut out to meter, meter to CU. If you leave 16mm before any 25mm tails then what's the point in altering anything?

shame on you tampering with dno equipment

 

[sparc]

no problem with a bit of disagreement

YOU cant put 25mm tails into meter, but meter man can next time he comes

Well, I'm thinking that the DNO / meter man won't - because that side of the meter isn't their They own everythin to and including the meter. They will say it's not their responsibility to upgrade it, but the customers.

 

[1shortcircuit]

YOU cant put 25mm tails into meter, but meter man can next time he comes

Legally - Correct

Physically - Incorrect

Put on new steel wire, non stamped seals. I wonder if any questions will be raised?

My meter had red temp seals on 6 years ago, that was before I replaced the consumer unit and had numerous meter readings done. Nothing was ever mentioned and the seals were never replaced for the steel wire type:thumbsup