Edition 18 garage cu

[Lucacini]

Hi

I’m after a bit of advice please. I recently had an old asbestos garage taken down and have replaced it with a brick structure inc a study done in line with building regs. I was going to reuse the old (fairly modern) board which was run from main cu with rcd but no rcd on garage board so I was told this would not be compliant nowadays. So I’ve replaced it with a garage cu from screwfix which has an rcd and mcbs. Happy days. However an electrician on our street just told me it’s still not edition 18 compliant because it should have an mcbo on each circuit rather than an rcd and mcbs. Is this correct? Many thanks (I know it needs inspection and sign off by an electrician as well - at the moment I have just connected the swa feed from house and swa out to my shed as I wanted to get power back on to shed - I was going to get an electrician to do the other circuits and then check what I’ve done)

 

[Dustydazzler]

I believe the only ‘difference’ between a 17th Ed board and 18th Ed boards is the 18th Ed is metal (non combust)

 

[James]

I believe the only ‘difference’ between a 17th Ed board and 18th Ed boards is the 18th Ed is metal (non combust)

However, is that of any importance in a building that is not a dwelling?

 

[Lucacini]

Thanks for the responses. Well the new board is metal so that’s good. And it is a dwelling - the garage is attached to house and includes an extra room as well as the garage. But the intention was for the cu to reside in the garage and supply the power and lighting circuits to the new room.

 

[Taylortwocities]

However an electrician on our street just told me it’s still not edition 18 compliant because it should have an mcbo on each circuit rather than an rcd and mcbs.

Not sure what an mcbo is (do you mean RCBO?). In any case, your local 'electrician' is not correct. An RCBO per circuit is not mandatory to comply with the 18th.

There is a reg (Separation of Circuits) that advises that installations should not have a single point of failure. That could lead one to the conclusion that a single up-front RCD is a single point of failure, and it's not good design to have this for a whole house (there are thousands of installations like this though). But in a domestic situation you have only one incoming feed which is protected by a service fuse. That also is a single point of failure.

This isn't a hospital ward with live-saving essential equipment that require 24 hour uninterrupted power. Its your garage with a couple of sockets and a light switch. Its fine.

 

[GeorgeCooke]

You don't need an RCD or RCBOs in the garage board if it is already protected by an RCD in the house. Something else you were incorrectly told.
There would be no discrimination. With a leakage fault either or both would trip.

 

[GeorgeCooke]

Hi

(I know it needs inspection and sign off by an electrician as well )

An electrician cannot sign off something he did not design or install, as the form he signs say that he designed and installed it.

 

[Dustydazzler]

An electrician cannot sign off something he did not design or install, as the form he signs say that he designed and installed it.

Unless your first name is Thomas and last name is
Nagy

 

[Lucacini]

Many thanks for the feedback (don’t you people sleep?!) Yes I meant RCBOs.

 

[Baddegg]

Sleep is for plumbers!.......5 words

 

[Dustydazzler]

Sleep..... yes after browsing here and checking YouTube for the latest sparky uploads to watch