EICR item 4.6 Presence of Main Linked Switch. Is an RCD acceptable?

[LeighSawczyn]

Hi All,

Does a BSEN61008 RCD fulfill the requirements of 537.1.4?
There is no other means of isolation, the tails come from the meter straight to the single 100A 30mA RCD protecting all circuits via BSEN60898 MCB's in a TT installation.

 

[Silly Sausage]

Yes.
See Table 53.4

 

[telectrix]

nowt wrong with that. it's a single point of isolation. only thing is that from 2008 (17th), you have no division of circuits between 2 or more RCDs.

 

[Deleted member 26818]

The requirement to divide an installation into circuits pre dates the 17the edition.

 

[LeighSawczyn]

Thanks Archy & Telectrix.
That's the problem with having an electronic copy of BS7671 one tends not to flick through the pages as you do in a book. If I'd looked in the book properly I would have seen table 53.4 on the previous page. DOH!

 

[telectrix]

The requirement to divide an installation into circuits pre dates the 17the edition.

i meant division of circuits between 2 or more RCDs, as in a single RCD upfront, if tripping, will isolate the whole installation.

 

[Deleted member 26818]

Same requirement in the 17th as was in the 16th, didn't even change the wording as far as I recall.

 

[telectrix]

but with 16th, buried cables did not require RCD protection, so lighting circuits and some others went on the non-RCD side of the |CU in a split board. thus leaving some of the installation live when the RCD tripped.

 

[Deleted member 26818]

Tel you made a big thing about the 17th edition requiring that installations be divided into circuits.
The fact is, that the 16th and most likely the 15th had the same requirements.
Also as this is a TT installation, it's very likely that it would had a single up front RCD under the 16th.

 

[LeighSawczyn]

Should I recommend a full RCBO upgrade with 100mA downstream Rcd protection?

 

[Deleted member 26818]

You can recommend such, however there is no requirement for such work to be carried out.
The current installation complies with the current Regulations, it's just that it's not ideal.

 

[Engineer54]

Should I recommend a full RCBO upgrade with 100mA downstream Rcd protection?

I think you mean upstream!! Far better on a TT system if that upstream front end device was an S type 100-300mA RCD rather than a straight 100-300mAmA device