16th Edition and RCDs?

[acvc]

Can anyone give me a quick answer on whether or not the 16th Edition permitted the non-use of RCDs for additional protection?

I've just had a call from a woman buying a house and she's described the consumer unit as having one rcd protecting cooker, shower and two socket circuits, but three lighting circuits not having rcd protection. the seller has an Elect Installation Cert issued 2005.

Cheers guys.

 

[acat]

House I am in has 16th edition board and I also have 3 lighting circuits without RCD protection. One of the main reasons for the 17th was increased usage of RCDs but cant give a difinite answer to your question. Bloke that did this house was NICEIC registered.


Hope that helps



Chris

 

[Risteard]

Can anyone give me a quick answer on whether or not the 16th Edition permitted the non-use of RCDs for additional protection?

I've just had a call from a woman buying a house and she's described the consumer unit as having one rcd protecting cooker, shower and two socket circuits, but three lighting circuits not having rcd protection. the seller has an Elect Installation Cert issued 2005.

Cheers guys.

30mA RCDs were required for socket outlets which could reasonably be expected to supply equipment outdoors. TT systems required protection of a 100mA RCD. Obviously this would need to be time delayed/S type for the purposes of discrimination.

Supplementary equipotential bonding was required in rooms containing bath/shower. Switches/sockets could not be installed inside such a room (except for a pullcord).

And I'm sure many other differences. If the EIC was issued in 2005 then the wiring could have been done in either harmonised or pre-harmonised colours (but not a mixture of both).

Not sure whether any of that helps.

If there's anything specific you're looking to find out I still have my copy of BS7671:2001 and the associated On-Site Guide, also a number of other 16th Edition-orientated books.

 

[Guest123]

As the chaps have said.....under the 16th only socket outlets likely to supply equipment outdoors required 30mA RCD protection, personally I put ALL sockets on 30mA side along with cooker (if control unit had a socket) and shower.

In TN systems fixed equipment (lights, boiler, immersion etc) didn't require any form of RCD protection hence the old style 100A main switch/30mA RCD split load boards as the Zs would be low enough for the MCB to achieve disconnection times.

As Risteard said TT systems required 100mA TD RCD/30mA RCD split load boards due to the high Ze (Ra) associated with them to achieve disconnection times.

 

[Risteard]

And of course lighting etc. required 5 second disconnection rather than the 0.4 seconds stipulated under the 17th.

 

[acvc]

Thanks for that guys. I've called her to say that at the 2005 point in time, it was compliant with Regs.

Cheers.

 

[Risteard]

An installation is always compared and contrasted with the current Regulations rather than those which may have been applicable at the time however.

 

[acvc]

Ta Risteard.

I was just really trying to ascertain whether it was a cowboy/diy job or not.

 

[Risteard]

Ta Risteard.

I was just really trying to ascertain whether it was a cowboy/diy job or not.

Fair enough. As I said, if you've any other questions let me know and I'll blow the cobwebs off the book.