Started to finish off my new workshop, have had a consumer unit professionally installed I now want to start the internal wiring myself. Simple question, do the sockets (four doubles in total) have to be on a ring main or can I wire them in series?
Assuming a 30/32A breaker for the circuit, you can either use a ring with 2.5 T+E or a radial (series) but would need 4mm cable (regs may ask for 6mm
now? not sure, stuff changes and is dependant on if it is buried/trunking etc )
ie the cable has to be able to take all the current from the breaker.
If you used a 16A breaker I guess you could use a radial in 2.5, but that could be a problem when it comes to use several things at once.
However, if this is all permanently connected then your work ought to be signed off by an electrician, and not being funny, if you are asking this
sort of question I think it would be wise! (I am not a sparky, but have done work and had it signed off)
IMHO,
House circuits are a ring. i.e. From consumer unit to the first socket, into the next, etc, etc, and back to the consumer unit.
I can't see any reason why the workshop is any different to lets say your kitchen, so the same principles apply.
You can't have enough sockets so think of a number, then double it. Go all the way round the four walls as well.
Nothing worse than having to keep unplugging this to put that in, then having to change it back. Surprising what needs to be
plugged in all the time.
It's also good to plug in tools where you are using them, rather than have leads draped across the floor.
Paul G
p.s.
Always put a socket by each door so you can run a lead outside.
[Edited on 25/11/15 by 907]
needs to be wired in a ring . i have a double socket every two meters round the wall at waist height. this means i can use power tools anywhere without plugging in an extension cable
I added some into the rafter space so that the cables hang down rather than trail over the floor,.. works well.
Ring main, 32amp breaker, 2.5 mm2 cable. If surface mounting I would run singles in round conduit, preferably metal in a workshop with metal clad sockets, although round plastic trunking is easier to work with and reasonably tough, would still use metal sockets and back boxes though, cheap enough now from screwfix etc.
2.5mm T&E in a ring main, as per the house. If running cables at waist height or below, I always suggest metal sockets as opposed to plastic ones - they tend to take knocks better than the plastic ones, which can shatter and leave exposed wires. I also used round conduit for anything below head height to be safe. But then again, my Mrs. does call me Dr. Doom!!
If its just the 2 double sockets and keeping to 17th edition regs then a 20A breaker radial circuit will be fine, in europe we're the one of the only country's still using a ring main circuit. It'll save you a bit of money on cabling as well if its a long run.
Thank you everyone for your replies, they were very useful, thank you.
Just to add to the problem
you can never have enough lighting,
steve
To add even more to the problem: In my garage I have a double socket on a roof beam, directly over the car, for a trickle charger, but every other socket is wired through a suitably rated switch by the door so on the way out I can make sure that nothing has been left powered up (radio, electric heater, etc.) In my case that meant radial wiring, sized and fused appropriately.
quote:
Originally posted by furryeggs
If its just the 2 double sockets and keeping to 17th edition regs then a 20A breaker radial circuit will be fine, in europe we're the one of the only country's still using a ring main circuit. It'll save you a bit of money on cabling as well if its a long run.
Not sure why so many people are saying it has to be a ring. Either configuration is acceptable with the appropriate cable and breaker combination -
you should choose the most appropriate for the circuit configuration.
In some situations a ring is a more efficient use of cable, and in others it's a huge waste. Depends if the ring naturally leads back in a loop
to the origin, or whether to complete the ring you just end up doubling back on yourself past all the sockets.
https://www.tlc-direct.co.uk/Book/6.3.3.htm
As an aside, ring circuits can be more dangerous with a fault because a break in the ring will not be evident - all outlets will continue working -
but current capacity of the cable has halved (approximately) as you now effectively have two radial circuits on undersized wire and the breaker is now
too high a value.
https://en.wikipedia.org/wiki/Ring_circuit
As long as your not running 8 welders at once 4 doubles is still ok for a radial with a 20A breaker.