Garage Sub Main BS1361

[slowrunner]

I am planning to run 6mm SWA from a main DB which is protected by a 40A fused switch. The SWA runs to a garage and is connected to a BS1361 40A, it then goes into an RCBO protected sub main board. Is the BS161 necessary at the sub main when there is 40A protection at the source?

Any advice would be greatly appreciated.

 

[telectrix]

be stupid to have 2 40A fuses in series. answer is no.

 

[MDJ]

. .

 

[slowrunner]

Many Thanks for a quick reply. I will assessed by NICEIC in a couple of weeks and thought it looked a bit OTT.

Cheers.

 

[Octopus]

Defo ditch the 1361 and what are you connecting in the garage - if you have a socket circuit then an RCBO is a must, if you have a lighting circuit and its all surface, just fit a MCB.

 

[shanky887614]

Defo ditch the 1361 and what are you connecting in the garage - if you have a socket circuit then an RCBO is a must, if you have a lighting circuit and its all surface, just fit a MCB.

Why bother if its a sub in garage just put an rcd in. Much cheaper and probably only a couple circuit's

 

[Octopus]

Why bother if its a sub in garage just put an rcd in. Much cheaper and probably only a couple circuit's

Well, simply because if you are out in the garage when its dark and the socket circuit tripped you would still have the lights!

 

[slowrunner]

A DIYr (previous owner) made it all a bit complicated not least, not connecting any external earths to the main ET of each board! All sorted with 3 new metal sub mains all containing RCBOs. I am just about to be assessed by NICEIC and wondered about BS1361's. The sub main supply goes from house and splits underground - one sub going to garage and the other to workshop. The BS1361 above is in the workshop which I will remove and I suppose that I should do the same with the garage BS1361 (it might even be 60A) not sure what would happen if I left it in? I am on a steep learning curve but glad to learn all I can.

Thanks for your comments.

 

[shanky887614]

Well, simply because if you are out in the garage when its dark and the socket circuit tripped you would still have the lights!

True but most cables are either surface or in conduit in a garage so dont require rcd under part p anyway.

Could even use rcd sockets

 

[slowrunner]

Thank you for your comment. The SWA in the garage is is surface mounted and the supply partly buried. I am newly qualified and mad keen at the moment hence wanting to do it right. The fog is getting a little thinner! Thanks guys for all your help.

 

[Octopus]

Please don't take this the wrong way, but are you sure that fitting a board in a garage is sufficiently "difficult, or taxing enough" to demonstrate competence?

 

[slowrunner]

It's one of a number of jobs and yes a lot more that a garage sub main is required to show competence.

 

[Octopus]

It's one of a number of jobs and yes a lot more that a garage sub main is required to show competence.

Good answer.

So back to the garage, ditch the 1361, fit a 2 way metal board, RCBO for sockets, MCB for lights (providing its surface) then do it nice and neat and double check your certs.

 

[GLENNSPARK]

Good answer.

So back to the garage, ditch the 1361, fit a 2 way metal board, RCBO for sockets, MCB for lights (providing its surface) then do it nice and neat and double check your certs.

well i wouldn`t mind knowing what the earthing arrangements were here first Murd...

 

[Engineer54]

well i wouldn`t mind knowing what the earthing arrangements were here first Murd...

Yep, what earthing system, and is there any extraneous metalwork/pipes in the workshop or garage that need main bonding to the sub-boards EMT??

Kind of wondering about this SWA cables underground split and if the continuity of the SWA is being maintained throughout?? Have you made any checking tests at all for this SWA cable??

 

[Engineer54]

Hmmm, ...i have just read your OP again and i'm now confused or i'm missing something!! So which is it, ...are you installing this 6mm cable or is it existing?? Make you're mind up!!

I am planning to run 6mm SWA from a main DB which is protected by a 40A fused switch. The SWA runs to a garage and is connected to a BS1361 40A, it then goes into an RCBO protected sub main board. Is the BS161 necessary at the sub main when there is 40A protection at the source?

A DIYr (previous owner) made it all a bit complicated not least, not connecting any external earths to the main ET of each board! All sorted with 3 new metal sub mains all containing RCBOs. I am just about to be assessed by NICEIC and wondered about BS1361's. The sub main supply goes from house and splits underground - one sub going to garage and the other to workshop.