Meter tails no rcd in stud wall

newfutile · Sep 5, 2022

During an EICR meter tails were found entering the cavity and coming down a stud wall to a consumer unit about 5 meters (direct distance) away.
they do have an isolator but no rcd or other protection .

as cables buried in a wall have to have (RCD) Residual Current Device at 30mA and generally tails over 3 meters are not permitted by DNO ,how can this comply?

Rockingit · Sep 5, 2022

They don't!

And more words

DPG · Sep 5, 2022

Is there no fuse either?

I hate meter tails in wall cavities.

newfutile · Sep 5, 2022

[ElectriciansForums.net] Meter tails no rcd in stud wall

Dustydazzler · Sep 5, 2022

As above I hate meter tails being snaked through a wall cavity or run up inside a stud wall with no way of knowing where they are actually sited

Made even worse if there is no RCD protection

littlespark · Sep 5, 2022

Has this photo been uploaded before?
It seems very familiar.

brianmoooore · Sep 5, 2022

If the tails are in the cavity, they are almost certainly more than 50mm below the surface, so no RCD protection required.
Still a rough way of installing them though.

Dustydazzler · Sep 5, 2022

littlespark said:
Has this photo been uploaded before?
It seems very familiar.

To be fair that is what 99% of new build meter boxes look like

timhoward · Sep 5, 2022

It looks like if they were pulled through properly they might be under 3m?

Dustydazzler · Sep 5, 2022

timhoward said:
It looks like if they were pulled through properly they might be under 3m?

All that slack snaking around the box sends my OCD into hyperdrive , I would be re-doing them w

Pretty Mouth · Sep 5, 2022

Are the tails definitely bare in the stud wall, or is it possible they have mechanical protection, complying with 522.6.204, (which I think would mean no RCD req'd)?

I have come across this a few years back in a new build, when putting up a cabinet in a toilet. The tails were installed in a steel stud wall, and my magnet picked up the mechanical protection. Thinking it was just another steel stud, I tried drilling it for a couple of minutes, before realising something was amiss and checked the other side of the wall to find the CU there!

HappyHippyDad · Sep 5, 2022

newfutile said:
During an EICR meter tails were found entering the cavity and coming down a stud wall to a consumer unit about 5 meters (direct distance) away.
they do have an isolator but no rcd or other protection .

as cables buried in a wall have to have (RCD) Residual Current Device at 30mA and generally tails over 3 meters are not permitted by DNO ,how can this comply?

As @Pretty Mouth has said in his post. I have twice now installed tails like this, both times I have used mechanical protection (3mm steel) which may not be visible without chiselling a bit of the wall out.

newfutile · Sep 5, 2022

littlespark said:
Has this photo been uploaded before?
It seems very familiar.

no i took this photo today

littlespark · Sep 5, 2022

Very similar picture from this thread…

Thread 'Quality of work in new builds'
Quality of work in new builds - https://www.electriciansforums.net/threads/quality-of-work-in-new-builds.187235/

But not exactly the same. As mentioned, it’s just the state of meter boxes nowadays on new builds.

davesparks · Sep 5, 2022

newfutile said:
During an EICR meter tails were found entering the cavity and coming down a stud wall to a consumer unit about 5 meters (direct distance) away.
they do have an isolator but no rcd or other protection .

as cables buried in a wall have to have (RCD) Residual Current Device at 30mA and generally tails over 3 meters are not permitted by DNO ,how can this comply?

Cables buried in a wall don't have to have RCD protection, they can have other forms of protection.

As you are carrying out an EICR it is very difficult to confirm whether or not correct protection has been installed. Examination of cables buried within walls, under floors etc is a standard limitation.

You need to make a judgement call as to whether it is likely to comply or not. When was it installed, what is the general standard of the installation, what records are available?

newfutile · Sep 6, 2022

It’s a fairly new build 2017 ,the EIC he left at the property does not mention mechanical protection, also the tails must be 8 -10 meters long

DPG · Sep 6, 2022

newfutile said:
It’s a fairly new build 2017 ,the EIC he left at the property does not mention mechanical protection, also the tails must be 8 -10 meters long

Definitely needs a fuse at source then.

Rockingit · Sep 6, 2022

It's the greater than 3m length with no upfront protection that does it.

Pretty Mouth · Sep 6, 2022

I watched that efixx vid, and re-watched it a couple of times, and then had a read through the regs mentioned.

433.3.1(iii), 434.3 (iv), and item (ii) of 434.2.1, these make me think that the tails are not restricted to 3m, as long as they are well protected mechanically, and that the DNO agrees that they are protected by their fuse.

Does anyone know under what circumstances a DNO would agree, or even disagree, to this?

davesparks · Sep 6, 2022

Pretty Mouth said:
I watched that efixx vid, and re-watched it a couple of times, and then had a read through the regs mentioned.

433.3.1(iii), 434.3 (iv), and item (ii) of 434.2.1, these make me think that the tails are not restricted to 3m, as long as they are well protected mechanically, and that the DNO agrees that they are protected by their fuse.

Does anyone know under what circumstances a DNO would agree, or even disagree, to this?

They'll probably never agree to it, certainly not for small supplies.
I've found that DNO's generally allow between 3 and 4 metres of tails maximum.

newfutile · Sep 7, 2022

thanks for all the interesting input and advice, i also put the same question to NICEIC but im less than impressed with the reply:

Good Afternoon,

Thank You For Your Enquiry

Based on the information provided, our guidance is as follows;

There is not a specific regulation within BS7671 which states whether or not supply tails with no RCD protection with a length of run greater than 3metres would result in a satisfactory or unsatisfactory outcome.

Do you feel that there is a safety concern or do you feel that an improvement can be made? Please could you also clarify how the tails have been installed.

Once we get further clarification from yourself than we may be able to assist further with your query.

Regards,

Risteard · Sep 7, 2022

newfutile said:
thanks for all the interesting input and advice, i also put the same question to NICEIC but im less than impressed with the reply:

Good Afternoon,

Thank You For Your Enquiry

Based on the information provided, our guidance is as follows;

There is not a specific regulation within BS7671 which states whether or not supply tails with no RCD protection with a length of run greater than 3metres would result in a satisfactory or unsatisfactory outcome.

Do you feel that there is a safety concern or do you feel that an improvement can be made? Please could you also clarify how the tails have been installed.

Once we get further clarification from yourself than we may be able to assist further with your query.

Regards,

Their response doesn't seem unreasonable. DNO conditions of supply and BS 7671 requirements are separate issues. It doesn't mean that the installation is not in breach of the former, however.

Baddegg · Sep 7, 2022

End of the day it makes no difference to you wht the outcome of the eicr is….so if concerned give it C2 or fi and put the report to the person paying

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