SWA to shed - agree with my proposal?

[sparky05084]

Hey all

Been quite some time since I've been on here so first off a big hello and hope everyone's well. Personally, I've gotten a dose of Man Flu but I just have to get on with it I suppose.

I'm after some advice really and any opinion's would be greatly appreciated. I am going to be starting a job this weekend that entails a partial rewire to the property and the installation of a new consumer unit. The con unit comprises RCBO's and I am considering putting the shed (will be fitted at a later date) on it's own individual circuit.

The shed itself will house a light, a socket and an alarm. You might ask why an alarm? well, that's what he wants so I'll fit one.

There is no facility on the rear kitchen wall to come off a socket and add an FCU, hence my proposal to run it from the new con unit in the house. I wonder if this is overkill because of the fact the shed will have such a minor current demand.

The shed will be located approx 2M from the rear wall so I thought I would run a 2.5 T&E to an adaptable weather proof box and then from there run a 2.5 SWA 3 core to a small dist board in the shed. Put it on 20A RCBO so it's RCD protected.

Not sure if this is the most practical or best design method. Am I missing something? What would you do?

Thanks guys

 

[Octopus]

Unless the T&E needs RCD protection, use an MCB in the house CU, then a small cu in the shed. RCBO for the sockets and MCB for the light(s).

In fact if its a partial rewire can't you run the SWA directly to the CU?

 

[sparky05084]

I was thinking about running it back to the CU yes. Probably me being a bit lazy

Why not RCBO the light(s)? Also, would you say 2.5 SWA is more than adequate?

Noticed you post a lot an help so cheers.

 

[Octopus]

You should think why do the lights in the shed need an RCBO??

 

[Redvanman]

Personally I'd use a garage CU which comes with a RCD as main switch they only cost £20 so works out cheaper than separate RCBO

 

[bigspark17]

Well if the 2.5 is <50mm in plaster it would require 30mA rcd protection! Which is fine, 30mA rcbo it in board then simple main switch and mcb's in garage. I think 2.5 is adaquate! But i wouldnt agrue aggainst a 6mm2, who knows what they will add in future

 

[Octopus]

Personally I'd use a garage CU which comes with a RCD as main switch they only cost £20 so works out cheaper than separate RCBO

Why do people always go for the cheapest solution?

RCBO the socket in the shed and MCB the lights - any fault on the sockets and the lights stay on!

And use a metal clad cu in the shed as its easier to terminate the SWA to it!

 

[sparky05084]

T&E will be protected in trunking from CU, run in floor space then out onto back wall via PVC conduit into adaptable box. Will consider putting it on 20A MCB then doing what Murdoch has suggested.

Still feel running the SWA direct to the CU would be better. Hhhhmmmmmmm.

 

[Octopus]

T&E will be protected in trunking from CU, run in floor space then out onto back wall via PVC conduit into adaptable box. Will consider putting it on 20A MCB then doing what Murdoch has suggested.

Still feel running the SWA direct to the CU would be better. Hhhhmmmmmmm.

Defintely, and consider 4mm 3c swa too!

 

[Redvanman]

Not just the cheapest option
if some ding dong decides to wire garden lights from the shed lassoing a bit of T&E across the garden at least it's got a bit if protection
plus on the cheapest option at least you giving the option to the customer there's nothing wrong with rcd lights it is only a shed plus if he T&E it from the CU then the whole installed would be RCDed
if he wanted to convert it into something more elaborate then as mentioned 6mm maybe better