Any Pelican electricians - Do I need a separate consumer unit for the garage?
 

We move into our new house 1st November, and I will be undertaking some major DIY renovation projects including upgrading the old style fuse box to a nice new consumer unit with circuit breakers. At the same time, I will be renovating the garage including upgrading the power supply to the garage for all the tools etc. As I am fitting a new consumer unit for the house, I am wondering if I run the garage circuits directly from the main consumer unit, or install an additional consumer unit in the garage?

If it is an attatched garage, no. As a generaliziation, you run the subpanel in the garage where the run is long enough that the you'd need very large wire for each circuit, at which point it makes sense to run a single large supply cable to the subpanel and then branch circuits.

There are tables in the electrical codes that show minimum wire size for x amps with a run of x feet.

Thank you Greg. My initial plan was to run a feed from the none RCD side of the main CU that I will install in the house using a 50A MCB to a separate waterproof CU in the garage, so that I can run independent circuits for lights, normal power ring and one for high power tools like a welder etc via independent MCBs. I was also considering using a RCD in the garage. Do you think this is overkill? I am keen to have the garage on a RCD, but do not want it on the same RCD as the other parts of the house...

edit: it is an attatched garage

Not entirely sure about your terminology(I don't speak Swedish electric :)). What you propose would work, its how my detatched garage is wired-a feed from before the main panel to a second "main panel) with a 100 amp breaker that then feeds the cable to the subpanel in the remote building.

What you propose is in fact a superior way to do things-the shorter the wire run, the less risk, as another generalization. Its not overkill by any means, but be sure that the single line to the subpanel is appropriately sized for 50 amps x number of feet-it'll likely end up being at least #6 wire (our terminology). Its not overkill if you can afford it.

Hmmmm, I was sure I was talking English electric, that is where I was educated :D CU - Consumer Unit, RCD - Residual Current Device, MCB - Miniature Circuit Breaker.....
Yes, I am proposing the same configuration as you have. I would feel happy having all the garage electrics running from a single MCB in the main CU if it was just a normal one light two power outlet garage. But just as everybody here, I want a fully powered Porsche play room :) And having had the education (sometimes the hard way - 240 AC can give a big sting!!) I would rather be extra safe than sorry.
Thank you for helping me, I am now convinced that I will get a secondary 8 way CU for the garage.

I'd do the second panel, and have provisions to attach a generator to it, for either a good spot to have the gen running and feedign your house, or to use the gen to power really hi-juice items like a welder, etc.

Second panel: Yes

Also consider GFI style breakers. Saved my wrinkled old a$$ more than once...

Thank you all for the comments, advice and support. Moneyguy1 I think the GFI breaker works the same way as the RCD does for a selected circuit in the CU.