Design

[High Tower]

I tell ya I could write a book.... The ramblings of a raging half wit!

 

[GStueyXR]

Hmmm, not a good start


I am perfectly well aware of what is a 'proper' installation, I just wanted to know if there is a distinct requirement' as in "2 rcd's HAVE to be used" ....

2 RCDs are not a requirement. 17th edition is non-stat. But, I guarantee that the NIC would reject your present installation on the grounds of non-compliance.

I refer you to my original answer 'RCBOs are your friend'.

 

[High Tower]

Now you are possibly going to have to stand in front of your customer and explain why you are going to have to replace the guts of their shiny new board probably at your own cost because you didn't design the installation properly to start with.

 

[GStueyXR]

Now you are possibly going to have to stand in front of your customer and explain why you are going to have to replace the guts of their shiny new board probably at your own cost because you didn't design the installation properly to start with.

And for gods sake, if they have any leaflets laying around, dont acuse them of spamming advertisements.

 

[stewart]

2 RCDs are not a requirement. 17th edition is non-stat. But, I guarantee that the NIC would reject your present installation on the grounds of non-compliance.

I refer you to my original answer 'RCBOs are your friend'.

Now, we getting somewhere lol. I happen to agree but in a fit of going along with client I chose to acquiesce and simply fit a single rcd controlled CU. I have regretted it but thought it complied.

So, I have 2 choices, either change it for a new CU , OR argue that it actually does comply.

I have decided that I will change the CU for one with 2 rcds, but I want to know is WHY my installation would be considered non-compliant? We are not talking new installation, just a new CU, so 4 mcb's and the only only one that could cause a hazard problem is if the lighting clicks the whole lot off..... so, just sticking the lighting on itw own separate rcbo doesn't remove the hazard ..... it might reduce the nuisance factor from a possible tripping of the freezer, but then, it not on a protected circuit so it difficult to be too concerned

So, reasons for non-compliance if you please

 

[GStueyXR]

So, reasons for non-compliance if you please

Would you agree that changing the OPD on a circuit is modifying that circuit?

Now go read about modifying a circuit and the requirement to ensure compliance.

5.1. Replacing a consumer unit in an existing installation
is an addition or alteration to that installation. The
work must therefore be designed, erected and
verified in accordance with the requirements of the
current edition of BS 7671, and must not impair the
safety of the existing installation. (Regulations​

110.1(xx) and 610.4 refer.)

 

[TPES]

Would it be an inconvenience or cause a hazard in the event of a fault?

Most likely in a domestic property this would.. So I would be fitting a dual RCD CU to comply to regs.

But if this was a garage with a 16a & 6a circuit with a RCD main incomer this wouldn't be much of an inconvenience.

 

[stewart]

I agree that fitting a new consumer unit comes within the Scope (110.1xx) and also it improves (assuming replacing like for like) that 610.4 is indeed verified as the installation is bound to be safer.

Interestingly, it is section 314.1 that is the nuisance factor

Fitting an RCBO should be mandatory! As soon as you go along the path of not fitting an RCBO you are effectively reducing the effectiveness of the installation. So, the path I have chosen, and that the one most preferred by Clients, is one of cheapness and necessarily not the best .

I maintain that I am fulfilling ALL requirements of 314.1 - as necessary - and that section (iv) is not statuary so much as guidance. Therefore, if following on with discussions with client it is agreed that a single RCD is acceptable I assume I can fulfil my obligations by sticking a label on the CU stating "Warning It only has ONE RCD" with an accompanying note in the certificate in the relevant box that draws attention to any deviation ...... mind you, as far as I can see, there is no argument, no deviation ..... only a lack of proper guidance over what has to be a 'compromise' as per normal occurrence in Domestic Installations

Mind you, I'm still going to replace the CU, I'm just annoyed I fitted it in the first place

(and I would fit RCBO's if they let me lol)

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No adverts were harmed in the making of this space

 

[Knobhead]

Sorry for butting in

But I do like your new signiture stewart

Think I'll run and hide now

 

[ezzzekiel]

wouldnt it of been better to do the research prior to the change? or gain a working knowledge of the regulations?

and i agree that GStueyXR Must stop with his constant advertising campaing

 

[Guest123]

Wouldn't one line of text linking to your website be enough Stuey???

 

[rocker]

Sticking a sticker on the CU won't decrease the percieved risk that would arise in the event of a fault tripping the RCD, i.e. someone falling down the stairs or stubbing their toe in the dark, will it?

That said, I'm not sure how much of an issue this really is. Most people know their way around their own house in the dark, but even that's not the point. I am concerned about somebody touching a live part and being electrocuted, decent earthing and an RCD will go some way to prevent that. Once the RCD has done it's job, I'm not particularly concerned; I use dual RCD boards because they DO minimise convenience and because the happy clapper clubs want us to, and to be honest they are normally just as cheap and just as easy to put in. But where should our conern end, we put in a new lighting pendant and the customer may get an energy saving bulb and they may drop it and they may get mercury poisoning from it..... where does it end?

 

[ezzzekiel]

Wouldn't one line of text linking to your website be enough Stuey???

just incase if you missed it the first time

 

[ezzzekiel]

..... where does it end?

its simple - it ends with you, thats where the buck stops regardless of what regulations you follow, i install all my work to the best of my ability and comply fully to my interpritation of the regulations - and that would always be my defence in court

 

[rocker]

its simple - it ends with you, thats where the buck stops regardless of what regulations you follow, i install all my work to the best of my ability and comply fully to my interpritation of the regulations - and that would always be my defence in court

Exactomondo! As long as fixed wiring is installed safely and to regulations, that is and should be where our involvement ends.