Putting a supply down to a shed.

[screech]

Hey guys.

Iv been asked to price a job, to supply a shed, with a couple of sockets and a light.

Iv got to trench some of the lawn and clip and rest, in all a 30m run.

The CU has an RCD main switch, and in the shed im thinking a 2way CU with MCBs for light and power, and put RCD sockets on.
Something iv never come accross, but will the RCD sockets trip the main RCD..?

Also, might be a silly question, im pricing to put nornal fittings in the shed, not IP rated stuff, as its a good new solid shed, would everyone else use normal plastic stuff??



cheers

 

[Deleted member 9648]

If the CU has a 30ma RCD main switch and you plan to come from that why the need for RCD sockets???

 

[monkeyelectric]

As long as it armoured for the whole run you could split the tails and use a switchfuse to supply the shed and then just put a garage consumer unit in there

 

[Coffeemad]

......a good solid new shed today will be a delapidated shed in 10 years time. Put the IP rated stuff in.

Trench the lawn to a depth between 300 - 450mm deep, don't want the client spiking his lawn and hitting the SWA.

Why not run cable direct to socket (16a radial) and spur off with switched fused spur to control the lights. Run all cables in black plastic conduit, its relatively quick, looks good and lasts for ages. don't forget to drill the little holes in the conduit boxes to let any condensation out.

 

[Hawk81]

As long as you think the shed is well sealed and no water will get into sockets and lights then i would be more than happy to fit normal plastic fittings. I dont understand why you would fit RCD sockets when the whole installation is covered by an RCD.

 

[Hawk81]

......a good solid new shed today will be a delapidated shed in 10 years time. Put the IP rated stuff in.

Trench the lawn to a depth between 300 - 450mm deep, don't want the client spiking his lawn and hitting the SWA.

Why not run cable direct to socket (16a radial) and spur off with switched fused spur to control the lights. Run all cables in black plastic conduit, its relatively quick, looks good and lasts for ages. don't forget to drill the little holes in the conduit boxes to let any condensation out.

How are we all expected to plan for what will be in 10 years time? That is impossible. The fella is trying to price to get the job now. It will still be done safely. Someone else could come in a price for the ordinary fitings and get the job.

 

[screech]

My only thought for the RCD sockets, was so it would only trip at the shed end rather than the whole house when/if she decides to cut through the mower cable!

Iv said the trenching will be at about 300 - 400mm deep, and i will also be putting it in some kind of ducting if i can find some.

To be honest, my plans went straight to putting a Small CU in the shed, didn't really think about terminating the SWA into a moulded box then then straight out into the circuits.


Cheers

 

[Jimmy Boy]

Am I reading this correctly ?

The CU has an RCD main switch, and in the shed im thinking a 2way CU with MCBs for light and power, and put RCD sockets on.
Something iv never come across, but will the RCD sockets trip the main RCD..?

RCD is covering whole primary CU ?

So where's discrimination ? Shed out all out ? Surely come off unprotected side or separate RCD to shed ?

 

[monkeyelectric]

Still think my way is best

 

[Jimmy Boy]

Still think my way is best

I should cocoa

 

[screech]

So where's discrimination ? Shed out all out ? Surely come off unprotected side or separate RCD to shed ?

Yea you was reading it correctly

I know what your saying, which is why i asked really, as im not sure if RCD sockets are differnt. Just like the plug in rcd adaptors, if one of them trips, the main rcd doesn't. Well, mine doesn't anyway


Splitting the tails and putting a separate switch fuse in would bealtight, but then the SWA wouldn't be protected. Plus theres not much room in the mains cupboard as it is


cheers

 

[Jimmy Boy]

Does it have an RCD as a main switch because of the supply type ? What are the supply characteristics ?

 

[super_stuey]

"but then the SWA wouldn't be protected"

It will be protected. It's SWA!!!

 

[Jimmy Boy]

That will be that dam 'Mechanical protection' thingy ?
LMAO

 

[Deleted member 9648]

Yea you was reading it correctly

I know what your saying, which is why i asked really, as im not sure if RCD sockets are differnt. Just like the plug in rcd adaptors, if one of them trips, the main rcd doesn't. Well, mine doesn't anyway


Splitting the tails and putting a separate switch fuse in would bealtight, but then the SWA wouldn't be protected. Plus theres not much room in the mains cupboard as it is


cheers

The answer to your OP is if there is an upfront 30ma RCD at the origin (not time delayed) and RCD's in the shed a fault in the shed will trip both RCD's. There are better ways of procceding as others have suggested, but if you are going to come from the main switch RCD there is no point in any additional RCD's in the shed.

 

[screech]

Iv spoken to them today, and they have had a quote that i need to beat.

I think iv decided how im going to do it, as they have now told me i can have a bit more room in the mains cupboard

Im gonna...
Split the tails out into henley blocks and into a 2 way CU with rcd, then out with SWA down to the shed into a moulded box, out to sockets, and spur down to the lights.

Should be able to get it cheaper than the other guys and get the job if i do it this way




cheers

 

[Welshsparky]

Are you qaulified?

 

[screech]

Yes I am...........

 

[monkeyelectric]

Iv spoken to them today, and they have had a quote that i need to beat.

I think iv decided how im going to do it, as they have now told me i can have a bit more room in the mains cupboard

Im gonna...
Split the tails out into henley blocks and into a 2 way CU with rcd, then out with SWA down to the shed into a moulded box, out to sockets, and spur down to the lights.

Should be able to get it cheaper than the other guys and get the job if i do it this way




cheers

Only problem with that is the sockets only overcurrent protection is the main cutout fuse you need a cu in the shed, i would put a switchfuse in the meter cupboard, run in swa all the way and into an insulated cu with rcd, 16a for sockets 6a for lights, job done and would'nt be too costly, you can't skimp on safety

 

[screech]

Only problem with that is the sockets only overcurrent protection is the main cutout fuse

Noo sorry I didn't say, would be on a 20amp mcb and 30ma rcd before going out in swa.

Cheers