Supply to Shed

[soulman]

Hi, after a bit of advice, i need to install a supply to a shed at the far end of a garden. There is to be a small consumer unit in the shed, feeding a couple of sockets and a 2 lights. The existing system is PME and the existing fuseboard has an upfront 30ma rcd, (use to be TT a few years ago). So the way i was thinking of doing it was to split the tails & install a small consumer unit next to the existing one a with a main switch and a 20a breaker to feed the circuit, pvc conduit up the side of the building into an adaptable box then SWA to the fuseboard in the shed. The fuseboard in the shed will have an upfront 30ma rcd & couple of breakers.

Anyone think of a better way or does this sound o.k

Cheers

 

[Benjamiin]

Where are you splitting the tails? If you split them after the up front rcd and then put another rcd in the shed you might get nuisance tripping as the rcds might fight each other!

 

[soulman]

No i am splitting before rcd, the customer wants a new consumer in the shed. I would normally take a supply from an existing unprotected fuse, but there isn't one. Also i dont need to protect the cable with an rcd going to the new fusebox on a TN system.

 

[Bobster]

Where are you splitting the tails? If you split them after the up front rcd and then put another rcd in the shed you might get nuisance tripping as the rcds might fight each other!

You mean there will be no discrimination...

 

[telectrix]

sounds OK so far, but have you calclulated the cable size wrt current and volt drop?

 

[Benjamiin]

In that case it sounds the best way to do it in my opinion, short of trenching or cleating an armoured, which is making work for yourself and cleating looks absolutely hideous!!!

 

[Benjamiin]

Reply to Rob

Yes, but I don't do posh words, simplicity works for me im afraid!

 

[soulman]

No calcs done yet. I am just looking at the most cost effective option didn't really want to have a consumer in the house as well as the one in the garage. I have spoken to a couple of sparks today who said i must rcd the supply to the shed. I said i would if it was tt, but buried or surface mounted on TN doesn't need it.

 

[Benjamiin]

No calcs done yet. I am just looking at the most cost effective option didn't really want to have a consumer in the house as well as the one in the garage. I have spoken to a couple of sparks today who said i must rcd the supply to the shed. I said i would if it was tt, but buried or surface mounted on TN doesn't need it.

Why don't you rcd protect anyway? Put the rcd board in the house and non rcd board in the shed, then everything is rcd protected?

 

[GLENNSPARK]

No calcs done yet. I am just looking at the most cost effective option didn't really want to have a consumer in the house as well as the one in the garage. I have spoken to a couple of sparks today who said i must rcd the supply to the shed. I said i would if it was tt, but buried or surface mounted on TN doesn't need it.

so did these electricians not understand the use of armoured subs to outbuildings on a TN?

 

[GLENNSPARK]

Why don't you rcd protect anyway? Put the rcd board in the house and non rcd board in the shed, then everything is rcd protected?

because you dont want to be traipsing into the house to reset the damn thing whenever it lets go....
gardening maybe?...muddy boots perhaps?...

 

[soulman]

The customer has specified that he doesn't want to go into the house to reset the rcd, if a lamp expires in the shed and trips the rcd. I dont think it is neccessary when using surface mounted conduit or surface or buried SWA on a TN system.

 

[MDJ]

Ive lost count with the amount of times I have said this but will say it once again, splitting the tails would mean you would need to install a isolator as you need a main switch to isolate all supplies, I know no-one does it, well I do, haha but thought I'd mention it again.

 

[Benjamiin]

[/QUOTE]because you dont want to be traipsing into the house to reset the damn thing whenever it lets go....
gardening maybe?...muddy boots perhaps?...[/QUOTE]

Good point Glenn! I'll just go back to my corner haha!

 

[GLENNSPARK]

because you dont want to be traipsing into the house to reset the damn thing whenever it lets go....
gardening maybe?...muddy boots perhaps?...[/QUOTE]

Good point Glenn! I'll just go back to my corner haha![/QUOTE]na....join in fella...
take no notice of me.....
i like being crabby....

 

[soulman]

MDJ. Thanks I did not know that there needs to be an isolator to isolate both supplies at once. Will the main switch on each consumer not do. What reg number is that.

Cheers

 

[MDJ]

no if you have 2 consumer units bud you need one isolator to be there for both, not sure of the reg at the moment, I have put my BGB back in the van, but now you have asked I will try to look tommorrow if I get time.

 

[soulman]

One question i didn't ask, adaptable outdoor box for pvc conduit to SWA any advice.

 

[GLENNSPARK]

One question i didn't ask, adaptable outdoor box for pvc conduit to SWA any advice.

just use an IP box...

 

[telectrix]

TBH, i can't find a reg. for that. looking at 537.1.4 it does not specifically stipulate a single isolator.