Size of meter tails

[Ray Tay]

So BS7671 is not mandatory, so if not complied with will pass a test by a Spark? I notice S/fix now have lots of metal consumer unit enclosures.

As clear as mud.

 

[Taylortwocities]

So BS7671 is not mandatory, so if not complied with will pass a test by a Spark?

It won't because the certificate that he signs specifically states that the installation complies with BS7671.

Also, and i am sure you have been told this before, the certificate says that the ELECTRICIAN who is signing has done the
DESIGN, INSTALLATION and TEST, all to BS7671. From your queries it would seem that you are doing the DESIGN and INSTALLATION. How will he be able to provide the certificate then, did you expect him to lie?

 

[PBC_1966]

Flameport, you write the DNO can only change or replace a main fuse to a lower rating, and not even a Part P Spark with the sealing machine. So a Spark cannot change a £5 fuse type for type or a lower rating? As PCB_1966 put you wrong on a major issue, I would need conformation of that.

The issue there is that the cut-out and main fuse belong to the supplier. Strictly speaking nobody except somebody working with the authority of the DNO or the metering company is supposed to pull it, replace it, or do anything else with it. In practice, some suppliers don't seem to make too much fuss if a seal is broken and the fuse pulled in order to replace a consumer unit or similar and will just re-seal it at some later time. Others can, apparently, be rather more upset about it.

 

[PBC_1966]

A plastic box is fitted with a RCD/incomer switch

A single RCD does not comply.

But neither does the typical split-load board with one RCD feeding multiple final circuits which British electricians have been happily installing all around the country for 20 years or more since that rule was introduced. I wonder how many note it as a departure on the certificate?

 

[EFLImpudence]

It all comes down to what you consider a danger and/or an inconvenience.

 

[Ray Tay]

PBC_1966, 'But neither does the typical split-load board with one RCD feeding multiple final circuits which British electricians have been happily installing all around the country for 20 years or more since that rule was introduced.'

The link I gave points that out. And these CU's are sold as 17th compliant. So one RCD/incomer in a metal box will comply.

Yep, all as clear as mud.

This thread..most appear confused..
//www.diynot.com/diy/threads/cu-change-pricing.438309/page-2

 

[Ray Tay]

Say a landlord gets in a Spark to check an installation. The landlords builders had one of his none Part P men do all the installation or extend an installation. He leaves the main fuse out. What does the inspecting Spark do? Fail it because it doesn't have a metal consumer unit box? Put back in the fuse and use his sealing machine? Or whatever?

I mean it is totally legal to DIY all the electrical system as long as it is signed off.

 

[PBC_1966]

It all comes down to what you consider a danger and/or an inconvenience.

Indeed. Many installations for many decades had a single earth-leakage protective device of some sort for the entire installation, be it the old voltage-operated ELCB, the older 500mA or so current-operated ELCB, or the newer 100mA or less RCCB/RCD.

For my last 17 years or so in "the old country" I lived with a single 100mA main RCCB, and yes, it was inconvenient on odd occasions - An element on the stove or in a kettle starting to go leaky, or trips due to thunderstorms in the area (rural with lots of overhead distribution). If I'd ever gotten around to completely revamping the wiring at that house, I would certainly have changed that to remove the inconvenience, and I would definitely not want a newer 30mA RCD as a main, for multiple reasons. So I wouldn't advise use of a single, main RCD when there are other options.

But from a pragmatic point of view, however, the result is no different than if the power to the building fails for some reason.

 

[PBC_1966]

Say a landlord gets in a Spark to check an installation. The landlords builders had one of his none Part P men do all the installation or extend an installation. He leaves the main fuse out.

Officially, they shouldn't be pulling the main fuse in the first place, as noted already, and if they've broken the seal to do so (possibly incurring the wrath of the supplier, possibly not) then they might as well replace it when the work is done and just leave it to be re-sealed later.

What does the inspecting Spark do? {.....} I mean it is totally legal to DIY all the electrical system as long as it is signed off.

And possibly not even that. The legalities now are that much extension and alteration work is not notifiable and must merely comply with the somewhat vague requirement of Part P of the Building Regulations to make "reasonable provision for safety." Certain work when not carried out by a member of an appropriate scheme is notifiable, which means that officially it should be notified to the local authority in advance, you pay an extortionate fee to said local authority for the "privilege," and then they'll most likely still want you to get a registered electrician to inspect and test at your own additional expense.

Electricians working to BS7671 within the various schemes cannot provide an installation certificate if they've had no part in doing the work themselves, but they can carry out an inspection and provide a report based upon the current requirements of BS7671. Note that failure to comply with every last rule in BS7671 doesn't necessarily mean that the installation will "fail inspection" though, although departures should be noted.

 

[Ray Tay]

PBC_1966, 'So I wouldn't advise use of a single, main RCD when there are other options.'

In this case the existing consumer unit looks modern with mcb's. To replace is a messy job in redecoration using an expensive metal unit box and 25mm tail back to the meter. And expensive. To me, fitting a 'metal' single box with an RCD/incomer with 25mm from meter to new RCD box, connect onto existing 16mm tails to the consumer unit and then having a 80A main fuse if a 100A fitted (by the Spark or DNO man), should do it. But some say its OK and others not. The householder is interested in safety not inconvenience. To get safety is going to cost fortune, when a simple RCD can do it all and make the installation a hell of a lot more safe than before. Some would stay unsafe rather than pay. Madness to me.

Clear as mud.

 

[Ray Tay]

PBC_1966, 'Officially, they shouldn't be pulling the main fuse in the first place, as noted already, and if they've broken the seal to do so (possibly incurring the wrath of the supplier, possibly not) then they might as well replace it when the work is done and just leave it to be re-sealed later.'

Will the man who does an 'inspection' reseal?

PBC_1966, 'Electricians working to BS7671 within the various schemes cannot provide an installation certificate if they've had no part in doing the work themselves, but they can carry out an inspection and provide a report based upon the current requirements of BS7671. Note that failure to comply with every last rule in BS7671 doesn't necessarily mean that the installation will "fail inspection" though, although departures should be noted.'

So get an inspection not an installation certificate.
'within the various schemes'? There is no Gas Safe equivalent for electricity.

So use a metal consumer unit (I assume not mandatory) and all RCBOs and you are pretty well there when getting an inspection.

PCB_1966 you are the only one to be clear on all this.

 

[ban-all-sheds]

Oops, Had too much to drink today - 0.0225 square inches is the intended measurement!

The intended measurement of what?

You kept on saying that a 0.0225mm² conductor could carry a continuous load of 100A, and got pretty shirty when you were told that was rubbish.

 

[ban-all-sheds]

PBC_1966 wrote: 'Except that there's no obligation to follow BS7671.'

Thank you. Just as I thought. The article I linked to and cut & pasted implies what you confirm.

Ray - you should be aware that PBC has a pathological hatred of the regulations, and will stop at nothing if he thinks he can persuade others to ignore them.

If you choose not to comply with BS 7671, can you tell us what alternative approach you will take to comply with Part P of the Building Regulations, where there is an absolute, legally enforceable, obligation to comply?

As PCB_1966 put you wrong on a major issue, I would need conformation of that.

PBC didn't "put him wrong", he came out with his usual "I absolutely hate the idea of the Wiring Regulations and I will do anything I can to get other people to ignore them" irresponsible propaganda.

Flameport, A plastic box with an RCD in like this does not comply? Are you serious?

Have you read 421.1.201?

 

[ban-all-sheds]

But neither does the typical split-load board with one RCD feeding multiple final circuits which British electricians have been happily installing all around the country for 20 years or more since that rule was introduced.

Not since it became, in practice, impossible to not have all circuits RCD protected.

 

[PBC_1966]

Not having come from a BS7671-centric British electrician's background, what I don't have is an absolute insistence that every last regulation within BS7671 needs to be followed, and an illogical approach adopted by some that something which was installed yesterday and considered pefectly fine (including by all the electricians working to BS7671 at the time) suddenly becomes "wrong" or even "dangerous" today just because a rule has been updated. And as comments elsewhere demonstrate, sometimes the rule changes are for the worse, not the better.