25mm (SWA) Sub Main To My Shed?

[Murdoch]

You mean organic growing plants, not plant and machinery?

There are an awful lot of sheds in those gardens. Is this "sheds with beds" land?

If he's in Slough than almost certainly!

 

[Connor Cox]

I do have the occasional joint can't deny that but no definitely don't live in Slough thank god we would run from the consumer unit but it's a old fuse board style and there's no more space left so what about running from henleys with a switched fuse? 

 

[Connor Cox]

Well I did a nhs server room last year and they only asked for a 32a supply - now I understand why they loose so many patient files they obviously need a bigger supply?! 

Haha poor management of files maybe I've decided 10mm swa should do it 

 

[apprentice87]

You do not size your cable based on the load mind.. It is based on the OCPD protecting the cable. So have a think about what OCPD you going to use, and EFLI not to mention, most importantly, earthing type used both for the supply, and also at the shed end..

john..

 

[Sidewinder]

With all that network kit, I hope that it's not TT, and that there are no RCD's involved.

They would need to be engineered out for reliability, then there are the regs on protective conductor current to consider.

 

[binky]

don't firk about with 10mm, bung in 25mm and have some spare capacity, the extra cost isn't that much. Run meter tails 25mm, from henley blocks to switch fuse, these normally come with 63A Fuse, but can be changed up when required.

Now, safety bit, can you post a picture of the main incoming point ie the main fuse for the house and any associated earthing. Exporting earths outside the equipotential zone (ie the house) can be dangerous. I would also suggest surge protection to protect all that sensitive gear.

 

[Lurch]

What I like about this is everyone saying you should just get rid of all the equipment instead of installing the correct cable.

It is unlikely you will pull anywhere near 50A with a couple of racks. I have downsized mine recently but even with a couple of old Supermicros, a G6 and a few other switches and odds and ends it was all still on one 13A plug, on the single 32A ring main supplying the entire house including the oven/washer/dishwasher. On paper the rack/lab was drawing well over a kW or 2, realistically it never drew more than a few hundred, except on startup maybe but this can be delayed to keep it sensible, and the UPS was well oversized so the entire rack enver actually needed to be started up completely.

Having said that, even if you spec it and decide that 40A is enough and for example that 10mm² cable was big enough, I would be inclined to go for something larger anyway as the majority of the job is connecting up and running the cable. To run a 16 or 25mm² and stick it on a 50 or 63/80A wouldn't really increase the overall cost by much percentage wise.

 

[Murdoch]

Wonder what size the main fuse is?

 

[Andy™]

might be a slow blow BS1202-1

 

[Blue Duck]

might be a slow blow BS1202-1

I dunno Andy, the quality  of 1202's has dropped significantly over the years...

:innocent