Electricity supply to garage

[Penners]

Better to use 2x RCBOs than 1x RCD, then when your power tool pops the power you're not plunged suddenly into darkness while holding the faulty spinning power tool.

Good point, NT, many thanks for your answers.

Thanks to everyone for your advice. I shall now get quotes for the job in the knowledge that no electrician can say to me "Oooh, no. You can't do that. The regs say you've got to do this." (The definition of "this" being something that costs four times as much).

Many thanks again.

 

[Penners]

When i asked about the metal in the garage I was meaning steel beams, water pipework etc.

Yes, I understand what you mean, thanks Tony. The garage will be timberframe, and there won't be any metal components or services.

I note your other detailed comments, thank you.

 

[tony]

Your house is protected by a rcd, adding anothere rcd or rcbo will not guarntee that that device will trip first.

This is called discrimination

Unless your house has a time delayed rcd, while working in the garage you might find that if a fault occurs all the power will go off.

What exactly are you planning on running in the garage, small workshop etc.

the total current demand has to be worked out, total length of cable, any correction factors, installation method etc, type of protection at origin of supply, max Zs etc.

Its not just a simple a chucking in a 4mm2.

Never heard of 80mm2 cable

 

[Jane Smith]

Never heard of 80mm2 cable

We're very exclusive.

 

[Penners]

What exactly are you planning on running in the garage, small workshop etc. the total current demand has to be worked out, total length of cable, any correction factors, installation method etc, type of protection at origin of supply, max Zs etc.

I'm just runnign small hobby-type woodworking machines. However, I'm sure that the electrician who does the installation will work out all the stuff like current, etc. I just want to be sure that I know broadly what is required, so that I don't get ripped off.

(I'm sure 95% of electricians are honest, but you can never be sure who the other 5% are!)

 

[chuckey]

Before you start, I would examine the proposed location of your fixed catenary hooks. The weight of 3 core SWA + catenary cable + hangers + wind loading + two fat pigeons, could easily pull out a lightly loaded single skin wall, which you are likely to have at the garage end. Also the hangers must them selves be clipped to the catenary or wire or they will slowly work themselves along to the ends.
I believe in burying the cable. There is very little cost involved, mark out trench (60p for box of kids chalks), pick up narrowest spade you have (£15 max if it has to be bought) and a crow bar/iron bar two feet long, lift up paving and dig trench 18" deep and 3" wide.. Bed the cable in a couple of inches of sand, top and bottom (£5 for 2 bags)). Top the sand off with cheapest bricks, paving edging to provide some protection. Ideally put down the tape which says "danger electricity" or failing that, red plastic tape. re-fill whats left of trench, replace paving. Cheaper then going to the gym!
frank

 

[Penners]

Thanks, Frank. It sounds easy when you note it down like that, but you haven't seen the builder's quote for lifting the drive pavers, trenching, backfilling, then relaying the pavers. No gym that charged that much would get my business! (Mind you, no gym is going to get my business anyway - they all seem to want me to do exercise stuff).

I'm quite happy about the strength of the proposed catenary fixing locations. Both ends can be secured to main timberframe members.

Thanks for your thoughts.