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My guess is that the IET are simply 10 years out of date, plus someone somewhere calculate the specification, then a sub committee adds 10% to that, and the main committee thinks - let's be in the safe side, and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

 

[sparc]

shame on you tampering with dno equipment

Pop quiz - in your experience, which is most likely to look after the safety interests of the the customer? Is it

a) the DNO, or
b) a responsible spark called in by the customer.

 

[jase]

round and round and round we go

 

[1shortcircuit]

shame on you tampering with dno equipment

Hey I posted earlier in the thread, My Magic Wand does the work not me

 

[flukey]

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.

doesnt matter what you regard meter tails as you arent allowed into the meter

 

[flukey]

Pop quiz - in your experience, which is most likely to look after the safety interests of the the customer? Is it

a) the DNO, or
b) a responsible spark called in by the customer.

hopefully the same person that looks after the spark when home owner gets accused of diddling the meter :lol:

 

[sparc]

round and round and round we go

Correct, but I still don't have a conclusive answer! Some people think the 25mm is not mandatory - you can make a calculation on loading, and use 16mm2 if appropriate. Others think you've got to upgrade to 25mm2 - no option - but say you can't take existing tails out of meter to replace.

I'm going call it quits now, but I would add that - in my experience - opening the part of the meter that gives access to the tail temination block - doesn't give you access to inside of meter. So the seals on the meter don't have to be opened. Maybe some older meters don't have a clear divide like this.

 

[flukey]

Correct, but I still don't have a conclusive answer!

because you dont listen

I'm going call it quits now, but I would add that - in my experience - opening the part of the meter that gives access to the tail temination block - doesn't give you access to inside of meter. So the seals on the meter don't have to be opened. Maybe some older meters don't have a clear divide like this.

but it does allow you to bypass the meter, that means free electricity

 

[1shortcircuit]

Correct, but I still don't have a conclusive answer!

An installation needs to comply with BS7671 to ensure good practice but is not law, however Building Regs say that work should comply with BS7671 which is law so in a rounadbout way it doesn't matter what you do because IF something were to happen then you'll get it from one side if not the other or both perhaps?

 

[Des 56]

Leave those meter seals intact
The cables from the cut out to the meter are not ours to play with
As flukey,the 25mm tails in the consumer unit can be jointed to whatever is existing,even if they are well undersized 6mm or such

The supplier can be notified to come and make that connection,it used to be £16.

They can then replace the cut out seal (that was removed for safety) at the same time if they want,or not,its their choice, their equipment, their responsibility

If they dont fit the new tails its not your problem, if the meter gets cooked, as long as the connection was requested the problem is theirs

 

[jase]

and to work on the meter would mean pulling the cutout which in theory means cutting the seals on the cutout!!! which of cousre you are not allowed to do :rolleyes2:

 

[flukey]

Leave those meter seals intact
The cables from the cut out to the meter are not ours to play with
As flukey,the 25mm tails in the consumer unit can be jointed to whatever is existing,even if they are well undersized 6mm or such

The supplier can be notified to come and make that connection,it used to be £16.

They can then replace the cut out seal (that was removed for safety) at the same time if they want,or not,its their choice, their equipment, their responsibility

If they dont fit the new tails its not your problem, if the meter gets cooked, as long as the connection was requested the problem is theirs

common sense prevails, thanks des, now time for a beer, or 10 :lol:

 

[Octopus]

Just like dragons den I'm out and about to unsubscribe from this eddy current of a thread!

 

[Geordie Spark]

no problem with a bit of disagreement

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

IF he can be bothered !!!!

 

[flukey]

IF he can be bothered !!!!

lol very true but that wouldnt be my concern

 

[ste mac]

The rotating disc electric meters are only rated at 80A, so should the cut-out fuse not be a maximum 80A?

DNO's - a law unto themselves!