Class 2 consumer units

[kerching]

Once the IET guide is out (due March I think), I'll post the gist of it as it's part of my subscription.

Good luck with that  :Salute

 

[Evans Electric]

I only fitted two metal domestic ones  since it kicked in this year .       My first thoughts on the lid  hinging upwards cannot be printed here until ................  calming down and giving it more thought ......  gravity prevents you from leaving it open ..although its a PITA having to hold it up while working on it.  

 

[Murdoch]

I only fitted two metal domestic ones  since it kicked in this year .       My first thoughts on the lid  hinging upwards cannot be printed here until ................  calming down and giving it more thought ......  gravity prevents you from leaving it open ..although its a PITA having to hold it up while working on it.  

Just take the cover off!

 

[NozSpark]

The only "work" that you have to do on the cover would be to put the stickers on.... I just do that with the cover off and on the floor

 

[Rob_the_rich]

I have mentioned here before about having to hold up the lid. It could be dangerous for both sparky and users to re-energise a tripped circuit whilst holding onto the installation's metalwork. I suspect that more deaths could be caused in this way than ever occurred by combusting CUs.

Manator, you have lost me, any more clues please? Unless you refer to BS EN 61439-3?

 

[kerching]

Just take the cover off!

Magnet?

works for me!

 

[steptoe]

Magnet?

works for me!

I thought they'd gone bust. :C

Bloody dodgy kitchen fitters doing electrics, whoda thunk it,? 

 

[Rob_the_rich]

I read it as.....

Anything that could potentially have up to a 25mm2 tail rammed into its terminations "IS Rather Similar".....

Whereas an accessory such as a shower or cooker switch that can only accommodate up to 10mm2 is not!

:Salute  

then why mention switchgear assemblies if it was all about the size of the cables? Would have made a lot more sense

Magnet?

works for me!

insulating tape?

 

[steptoe]

Apply enough heat to most materials and they become combustible 

Has the LFB defined an actual temperature,? 

 

[Manator]

I have mentioned here before about having to hold up the lid. It could be dangerous for both sparky and users to re-energise a tripped circuit whilst holding onto the installation's metalwork. I suspect that more deaths could be caused in this way than ever occurred by combusting CUs.

Manator, you have lost me, any more clues please? Unless you refer to BS EN 61439-3?

The risk of electrification due to metal consumer units was one of the primary considerations for the introduction of plastic units.

That in itself is another conversation entirely.

When any new addition to a regulation is written, it is acceptable to assume that not all angles can be reasonably encountered. Its not the engineers who decide what goes into the regulation, its the lawyers that write it. Or to be more precise a technical writer issues a draft, a legally minded firm look for the correct way to introduce that thought. The result is often debated, as is this one, but there remains options, such as get out clauses, and adaptation of the requirement.

You mentioned previously in one of your posts that BS7671 is a guide and that you can deviate from it. That statement is true, however you have to be very sure to do this in reality, as other standards and statute laws become more apparent and binding.

The type test testing alone is out of the remit of most, if not all electricians. If you read the BEAMA report you will see such a legal statement, that invalidates your opinion. That statement is given directly after your assumption.

I am hoping people will read.

 

[Rob_the_rich]

you mean "The above table provides general guidance and is not intended to be an exhaustive list of

inclusions and exclusions."? So an RCD could be in or out of scope, just not listed.

 

[Manator]

you mean "The above table provides general guidance and is not intended to be an exhaustive list of

inclusions and exclusions."? So an RCD could be in or out of scope, just not listed.

I have scoobed you because you went back and read it.

You are right, the thing is we do not decide what is in or out, they do. That is the most important message here.

 

[Rob_the_rich]

I see now, they decide.

An RCCB on its own does not conform to BS EN 61439-3, how does putting it in an enclosure (plastic or metal) make it comply? Because it must comply with it to comply with 421.1.201, if it is indeed a similar switchgear assembly.

 

[Rob_the_rich]

OK I have just got off the phone to niceic tech helpline and the very nice man there said that an mccb in an enclosure does not constitute a "similar switchgear assembly" and can therefore quite happily sit in a plastic enclosure.

That is their view at the moment.

Seems they have decided.

 

[Rob_the_rich]

Ask for it in writing......

(So when they change their minds and you get pulled on assessment)......

Just thinking ahead

I work in London and have yet to see a TT install

Good thinking though.

I tried the iet helpline but they are at lunch til 2

 

[Essex1]

That is just not right.  There is something about the way you worded that post that makes me think it is a MCB in an adaptable box.  Which I agree could be put in a plastic box.  However, a purpose built 2 way enclosure is classed a similar assembly IMO.

 

[Rob_the_rich]

That is just not right.  There is something about the way you worded that post that makes me think it is a MCB in an adaptable box.  Which I agree could be put in a plastic box.  However, a purpose built 2 way enclosure is classed a similar assembly IMO.

What is the difference between an mcb providing overload protection and an mccb providing fault protection? Both are single items of equipment and as such are not assemblies, so can go in their own plastic boxes.

 

[Essex1]

BEAMA state -   "Similar switchgear assemblies" are assemblies used for the same fundamental application as consumer units.

 

[Rob_the_rich]

read the definition of a consumer unit in part 2 of bs7671 and explain how an mccb in an enclosure can be defined as a consumer unit.

I read it as a type-tested assembly of a DP switch and a fuse/mcb/rcd

If you were to buy a metal 2-way box and put an mccb in there. How does that comply with BS EN 61439-3? Unless both the enclosure and the mccb were made by the same manufacturer and were tested as such under that standard. They can't be AFAIK since they do not constitute an assembly and do not come under that standard.

 

[Essex1]

read the definition of a consumer unit in part 2 of bs7671 and explain how an mccb in an enclosure can be defined as a consumer unit.

I read it as a type-tested assembly of a DP switch and a fuse/mcb/rcd

If you were to buy a metal 2-way box and put an mccb in there. How does that comply with BS EN 61439-3? Unless both the enclosure and the mccb were made by the same manufacturer and were tested as such under that standard. They can't be AFAIK since they do not constitute an assembly and do not come under that standard.

The regulation does not say "or similar consumer unit assemblies" it says "Similar switchgear assemblies"

The definition of 'Switchgear' is what we should be looking at - 'An assembly of main and auxiliary switching equipment for operation, regulation, protection or other control of an electrical installation'.