17Th Edition Amend 3 Metal Consumer Units - Cable Entry.

[Essex1]

But they didn't & thats part of the problem.

I believe that would then leave the item unfit for sale and to offer it for sale would be illegal.

 

[Sidewinder]

I believe that would then leave the item unfit for sale and to offer it for sale would be illegal.

Correct, this is one of the MAJOR issues, why do you think the blame & the solution has been landed with the installers?

Money talks.

 

[SBS Dave]

Hi Noz,

Glad you like my mini-trunking stand-off frame idea. It's easy, effective and cheap.

Another good idea (IMHO), is the 3-gland solution for meter tails entry.

The attached photos show a sample metal  board, which has now been replaced by my current range.

It is an 8-mod/6-way box, fitted with 6 x Compacts. The tails entry is via 3 x plastic glands @ less than £1.50 total.

There is no sealing required, since all cables are gripped fully and therefore sealed.

So if anybody interested in trying it??. If so, then.

YOU CAN HAVE THIS BOX (box only)  FREE OF CHARGE.

I will leave the glands in place and I will label it up to you exact requirements. All you need to do is to find a suitable job for the box and order the required number of Compacts. Hopefully you will post a photo of the finished job afterwards.

SBS Dave

 

[Sidewinder]

The only issue with that Dave, is Reg 521.5.1

 

[ProDave]

Isn't there an issue with eddy currents if L and N cables go through different holes?

Have you cut a slot between the holes to prevent that being an issue?

 

[SBS Dave]

You may recall on earlier posts, that I not only showed photos of the three holes being linked together with slots, I also suggested using a nibbler to cut the slots.

The good news is, that the arrangement is so f***ing neat, that you didn't see the slots. I have bridged the slots with white PVC tape so it provides a decent IP rating.

So, Sidewinder, since that was your only issue, are going to give it a try?

You are correct ProDave, there would be the issue with the situation you mention, but not in this case.

SBS Dave

 

[Sidewinder]

You may recall on earlier posts, that I not only showed photos of the three holes being linked together with slots, I also suggested using a nibbler to cut the slots.

The good news is, that the arrangement is so f***ing neat, that you didn't see the slots. I have bridged the slots with white PVC tape so it provides a decent IP rating.

So, Sidewinder, since that was your only issue, are going to give it a try?

...

SBS Dave

No I didn't remember Dave!

Typical of me really, sorry.

I may well try one, the thing is I don't do many CU changes, because I do so little domestic, it hardly affects me anyway.

The biggest use for me is the haemodialysis installations, & I will have to work on the client to move away from branded stuff from local suppliers where we can pick up devices quickly from multiple sources in the event of a failure or an issue, e.g. damage for example.

Plus, the splitting off the 3 circuits (now, it was 2) onto sperate RCD's doesn't give us much if any advantage, because the lighting circuit only powers one M3 em light.

The two power circuits, are feeding interlinked equipment (not electrically interlinked in the BS7671 way), they have a serial comms link, and one won't run without the other anyway, we did used to put them on one circuit for that very reason, but, MI's suggest two circuits, which suits me because it means a 5 way board realistically which gives me room for the additional earthing within the board, rather than putting an external ERB in, I can use the board, less chance of any fiddling, IYKWIM.

 

[SBS Dave]

The first photo shows an example of the linked hole drilling, that I mentioned earlier .

The second photo shows a rough, handmade back knockout insulation idea, made from busbar insulator. If I offered it as a supplied item, it would be made to a better standard. It is fairly secure as it is, but you could also glue it in place, just to be sure.

SBS Dave

 

[Rob_the_rich]

It does look neat Dave. Perhaps too neat? There would be a small number of EICRs with codes for it due to cursory visual inspections.

I am no expert with induced currents but do the slots need to be at least as wide as the copper diameter?

I noticed the box with the mcbs it it has two large circular knockouts, is there a rectangular one too?

And with at least 3 sizes of circular knockouts, why doesn't the manuf make blind pvc grommets for them?

Sorry for all the Q's, I like the idea of busbar insulation for the knockout/nibbled edges.

Thanks Dave

 

[NozSpark]

I was thing myself that a label might be required to let others know that the slot is there...

Eddy currents can't jump gaps and as it's effectively one (strangely shaped) hole then it'll be fine

 

[Essex1]

I do think it will get comments on the periodic testing when it takes place. I don't think it is as good as a Wiska gland.

 

[SBS Dave]

Hi Rob,

The slot idea is not mine and is an established method for eliminating eddy currents. I have just applied it to multiple glands.

The photo of the box shows vertical oval knockouts, but that was an earlier sample. My current product has square knockouts.

That is why I am recommending rigid insulation, in the form of busbar insulator, of which I have about 70 metres in stock.

The fact that the linked holes might attract comments on an EICR doesn't alter the fact that it is a legitimate setup and satisfies the Regs.

Hi Essex1,

I didn't say it was better than a Wiska gland, only that it was cheaper. However, I would be interested in your views on what makes it inferior to a Wiska gland.

SBS Dave

 

[Essex1]

Hi Rob,

The slot idea is not mine and is an established method for eliminating eddy currents. I have just applied it to multiple glands.

The photo of the box shows vertical oval knockouts, but that was an earlier sample. My current product has square knockouts.

That is why I am recommending rigid insulation, in the form of busbar insulator, of which I have about 70 metres in stock.

The fact that the linked holes might attract comments on an EICR doesn't alter the fact that it is a legitimate setup and satisfies the Regs.

Hi Essex1,

I didn't say it was better than a Wiska gland, only that it was cheaper. However, I would be interested in your views on what makes it inferior to a Wiska gland.

SBS Dave

Hi mate. Technically of course it is not inferior in any way. It is just my personal opinion that a Wiska gland or similar looks a better job and is obviously less work. I do also believe that it would leave installers open to criticism from future testers seeing 3 stuffing glands and assuming (wrongly) that they are 3 separate holes. TBH I would not like to see that method of installing tails. Again just preference.

 

[SBS Dave]

Hi Essex1,

At least we agree that both methods are technically equal.

Whether a Wiska gland looks better or not is of course, as you rightly point out, a matter of personal opinion..

I imagine you will not be taking up my offer of the free metal box.

My main interest however, is what is in the box. In the interest of open debate and customer feedback, I would welcome your opinion on RCBOs in general and my Compact RCBOs in particular.

SBS Dave

 

[Essex1]

Hi Essex1,

At least we agree that both methods are technically equal.

Whether a Wiska gland looks better or not is of course, as you rightly point out, a matter of personal opinion..

I imagine you will not be taking up my offer of the free metal box.

My main interest however, is what is in the box. In the interest of open debate and customer feedback, I would welcome your opinion on RCBOs in general and my Compact RCBOs in particular.

SBS Dave

No I won't Dave but I wish you well. That is weird. I swear to God when I saw your RCBOs I thought to myself 'wow! - they are nice and compact'. There is no doubt these RCBOs will make a huge difference to installation. Especially in smaller consumer units. I suppose the magic question is cost. Now I do very little domestic BUT I would definetely like to try your gear next time we do.

PS - I think it is great that you seek feedback from the guys on the ground. It is the key to being successful IMO.

To expand on RCBOs as a whole I think build quality is very important. Not just of the RCBOs/MCBs but the complete CU/DB. What you don't want is twisting when tightening up terminals. You want a nice area to loop your live, neutral and earth cables. You do not want a functional earth on your RCBO. Some really cheap RCBOs you can visibly see spitting when you tighten up. This is not good.

From a customers point of view they want to see a complete CU looking like it all fits together nicely. The lid fits nicely and the RCBOs/MCBs line up square. Some room for labels to go nicely in - preferably on the inside of they lid smit can be hidden.

I also like the newer boards having tail clamps. There is also a CU that gives you downward facing terminals for bottom entry tails. These are really great ideas IMO.

 

[steptoe]

Hi mate. Technically of course it is not inferior in any way. It is just my personal opinion that a Wiska gland or similar looks a better job and is obviously less work. I do also believe that it would leave installers open to criticism from future testers seeing 3 stuffing glands and assuming (wrongly) that they are 3 separate holes. TBH I would not like to see that method of installing tails. Again just preference.

that would be incompetent testers then,

that should not be doing any testing,

we cannot justify for all the idiots out there,

next we will be using lead sheath non combustible cable,  :slap    what ***** will propose such a thing next,,,????  LFB? probably,,,,

in all seriousness though,

for every good idea, there is a better quality of ***** out there,

we dont make everything in plastic with plastic screws just in case some tester pulls up a dry-liner box for having no earth tab,

 

[Andy™]

as above, if i saw any glands installed like that, then i would be checking for a slot before noting it. if anyone does note it on a report then they shouldnt be doing them

 

[SLIPSHOD & SLAPDASH]

I have seen many with glands like that,  without the slots  ;

 

[SBS Dave]

The previous free box offer was taken up by a long standing non-Forum NAPIT customer, who liked the 3-gland idea.



The attached photos are of another sample board I was evaluating and I am offering this one

FREE OF CHARGE (when supplied as a complete DB, with RCBOs of your choice)

It is a 14-mod/12-way box, with knockouts on the back, but no knockouts at all on the side walls.

This means you can choose any arrangement you want. It is better for Compacts, but it can be used, still with dropdown door, with the neutral and earth bars at the bottom, for Standard RCBOs.

I have also fitted a mini-trunking stand-off base, with a notch to accept incoming cables, but that can be pulled off if necessary.

Whoever takes up the offer, I will be happy to customise it to your own specification.

SBS Dave

 

[ProDave]

Re metal CU's and cable entries.

I have just fitted a Hager metal board in my new build. It has a whole row of 20mm knock outs along the top and bottom, and larger round knock outs on each side (perfect for gland for large SWA entry), plus rectangular knock outs on the back.

That seems pretty versatile and should cover all bases.

What are other makes of metal CU offering?

In contrast, I had a CEF rep visit me today. One thing he was keen to show me was their own brand (M2) metal CU's which only had rear knock outs and side knock outs, none on the top or bottom.  I pointed out how limiting that was and showed him my Hager board.

It would be good if forum members as they install different makes of the new metal CU's could post a mini review of them, including their provision for cable entry knock outs.  That information is vital for choosing a CU as a replacement as it needs to match the installation.