I want to put a tent in the loft. I dont have power in the loft and dont want to run off the ring main cos we use portable radiators all over the house.

So I want to run a line from the fuse box to a subbox in the attic.
I plan on using this as a subbox.....
http://www.screwfix.com/prods/65276/Electr...-Insulated-CSU#

From the subbox I want an MCB to each light, one to fans etc.



My question is....
Can I run a one-way cable from the fusebox to the subbox, without the need of a return to the fusebox?

Many Thanks

yes you can depending on what you want run up there (use suitable size cable etc)
but instead of mcb's ...i'd use rcbo's offering overoad protection and giving protection from the live and neutral should a fault occur

Many Thanks for the reply. Im undecided on rcbos or rcd sockets. Id imagine its gonna be whichever is cheapest unfortunately. Hopefully RCBOs!

RCBO's are more pricey...just use them on the lights would be best

A 2 way Volex RCD 63A unit would suffice. You can get then with the fuses already installed, a 16A for new the ring main (to run the whole grow from) & a 6A for your light in the loft so you can get to & from your tent without accidents! - You can run that unit from a 32A fuse in your main house Fuse board with confidence.

I have wired many rooms successfully like this (only one grow room I might add! ) . The other rooms have been running for 7 years now & the 6A powers 7 x 50W halogen bulbs (350W) all off the 6A it only trips when one of the halogens blow, but halogens are bastards for tripping even 32A units! But that is another story altogether!

My GR has this RCD unit I describe, so does my garage. My GR & clone room uses 3 Ruck fans, 3 circulation fans, a 600W HPS, a 110W flourescent, a 1000W oil rad & a 400W panel heater & a couple of water pumps & heaters.

Don't overkill & do a huge 32A ringmain though, 16A is plenty plenty unless you want to run several 1000W bulbs & many heaters If you rate the fuses too high they might as well not be there at all The main board can be as high as you like, I am talking the individual fuses, but the individual fuses must not exceed the main RCD unit capacity

Just wire it safely & descretely & get a qualified elecrtician, or at least an 'in the know' handyman who has done it before if in any doubt at all.

Good Luck

Thanks for the reply.

Ive now gone for an MK 4 way csu with a main switch, 30ma rcd, 6a MCB for fans and light to see (and whatever else) and 16a MCB for the 3 600w.

Ive been in the property business for a while so will do it myself but I know 2 sound electricians if I need help. tbh I always thought it was ok not to return to the fuse board.... I had a building surveyor tell me otherwise a couple of weeks ago (we were talking about circuits for lights) He was simply wrong.

The electrics in our house are shite! so ive just gotta do what I plan.

Many Thanks