RCD Spur

[sonobit]

Hi guys iam about to wire up a boilerfrom a FCU of the ring main, but the ring main isnt RCD protected, so do i need to protect my spur with a RCD FCU? because the customer dosent want the added expense of me testing the ring main and installing an RCBO to protect all the sockets. Or does the spur not need RCD protection? what then do i write on the minor works cert for the RCD part?

 

[Mr Mark Sparks]

stand by for a difference of opinions!!

i say if you add to a circuit you are responsible for making sure the whole circuit complies not just the addition
so fit a normal spur and use the money you would spend on the rcd spur to fit an rcbo or rcd at the mains

 

[Phil Mumford]

If the new wiring is surface you are not required to provide RCD protection for it or the old circuit.

Obviously you can only carry out this work if the earthing and mains bonding are up to scratch.

 

[sonobit]

Thanks guys, the wiring is not surface and the CU is a old rewire able fuse board so cant really install a RCBO there either. sorry should of explained that a bit better before.

 

[electricAl]

Have to say i`m of the same mind as Mark on this one.

& as suggested, a very contentious issue that splits us iinto two groups.

I can easily see Phil` point - it is tempting to just apply the requirements of the 17th Edition to the extended section. But even if the OP feels comfortable ignoring that S/Os need 30mA protection - & many did even under the 16th - you have a responsibility to ensure the supplying cct (the ring) can carry the additional loading. This would be impossible to due without testing the RFC...

because the customer dosent want the added expense of me testing the ring main and installing an RCBO to protect all the sockets.

An average customer then

They wouldn`t have us test anything if it works. But making it work isn`t our job brief - making it work safely is. They won`t understand the significance of RFC testing, but you should. We all know the boiler isn`t gonna add much extra loading, but without testing the cct first, how the hell would you know it isn`t bridged/discontinuous already? Only after establishing its all good can you proceed to deliberate on where to put the RCD.
As Phil said, you must check all Earthing & Bonding is upto at least min requirements.
And why would we go to the trouble? Cos our Part P body says we have to? Cos it can be seen? Hopefully not.
Hopefully,because we understand it must be upto the task asked of it - just like the Ring