mikew1972 i don't think what you've drawn is right if i'm right in my understanding from Sparky James.

will the RCD not trip if the wire from the existing socket is overloaded??

I think in the last pic, he has changed your spur from a spur into a proper ringmain connection, which is the way it should be done.

With your spur from a spur, the section of wire from the ringmain socket to the first spur is going to be the weakest point in the circuit, as if you plugged a 13amp device into both sockets on the spurs, that wire would have 26amps running through it which could cause overheating and failure of the insulation.

but that would mean that my existing socket would have 4 cables coming from it?

No it would just have 2... basically its power from the mains, and then a lead connecting to the next socket in the line...

Yes the ring solution is the best way and to do it properly you will have split the ring somewhere. This can be done with junction boxes or with through crimps in the back of a socketbox but both ways have there problems.


RCD's

RCD's have no built in overload protection they are a earth leakage device. Basically they monitor the electricity going to a given load down the Live conductor and then look for the same load coming back up the Neutral. If there is a significant difference (like 15-30mA for a 30mA device, leaking down to earth or another neutral on a different rcd or no rcd at all) they trip. The current rating on a RCD is its maximum design current like on a normal switch.

RCD's will not clear live to neutral faults

RCBO's provide both earth leakage and overload protection in one unit.

MCB's/Fuses provide overload and short circuit protection and can clear earthshorts circuits as well but require high fault currents to acheive this.
A 32A type B MCB requires a fault current of 160A to trip out within 0.1 of a second but a 32A type D MCB requires well over 300A. This is why RCD's are used to limit the current required to clear earth faults.

so in my existing socket i will have four cables, but i only need to connect two of them to the socket and join the other two together which would at it in to the circuit.

what can i use to stop the two joining cables touching the metal casing?

can i not run one cable from the existing socket to a 13amp fuse box unit, then run two single cables from that to each of the plugs?

As for what you use to stop the cables touching the metal casing, that would suggest you were going to twist them together or something ???? you would normally use insulated through crimps crimped using a ratchet crimpoing tool. Depending on room in the backbox, 30A connector block may be used. or you can now get some wago type connectors which you just push the cables into . If you want to go down the spur route then just put the spur next to the existing socket, then feed it from the existing socket and the load will be the two new sockets, but if you do this remember you will only ever be able to draw a maximum of 13A from all your two new sockets combined.It depends on what your proposing to use these two new sockets for really. May i suggest next time you start a job like this that you seek advice before doing it to save hassles later on.

Nick

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If it isnt broke dont bloody touch it until it bloody well is and if it is broke then make drawing of the connections before you remove the broken one and replace with a new one LoL

yer i'll have to remember that i didn't find this site until the other day., and didn't realise how helpful people where.

one plug is for a tv and the other probably for a lamp. would the fuse be to small for these appliances?

the casing is only 25mm deap, would you suggest 35mm?

if you where to extend the ring the cables could be joined with insulated through crimps blue ones. But you need to use the proper rachet tool not a crappy thing that costs 2 quid from lidle.

A TV and a lamp would struggle to use 1.5Amps but still the cables need to be protected.

I would stick a 13a unswitched spur in and enjoy.

like the following

yes if you like or you can stay with the daisy chain as already fitted.

i think i'll go for the safer option and put a unswitched fuse in.

thanks for everybodies help, really appreciate it.

Be thankful for small mercies, eh?

If you hadn't done that then you wouldn't have posted here and you wouldn't have found out that you'd made a dangerous and possibly unlawful change to your wiring.

A classic example of an unknown unknown.

Please, for everyone's sake, especially yours, take the time to learn things before you just dive in without knowing how to do it properly and just hoping you get it right.


USEFUL REFERENCE BOOKS

IMPORTANT NOTE - when buying books from Amazon, seek confirmation that they are the latest versions.


http://www.amazon.co.uk/exec/obidos/ASIN/027644079X

http://www.amazon.co.uk/exec/obidos/ASIN/0007231938


This one is only available second-hand now, and will be out of date in some respects, e.g. cable colours, bathroom zones etc, but will still be a useful primer on the basic structure of house wiring systems:

http://www.amazon.co.uk/s/ref=nb_ss_w_h ... &x=22&y=21


. . . . .


The next 3 are essential.


http://www.amazon.co.uk/exec/obidos/ASIN/0863418546

http://www.amazon.co.uk/exec/obidos/ASIN/0863418627 or http://www.theiet.org/publishing/books/ ... dition.cfm

http://www.amazon.co.uk/exec/obidos/ASIN/0953788555 or http://www.tlc-direct.co.uk/Products/TLGUIDE.html


. . . . .


The next three are pretty handy guides, the Amicus ones being small enough to fit in your toolbox.:


http://www.jmtrainingshop.co.uk/partPBook.php or http://www.amazon.co.uk/exec/obidos/ASIN/0955479304

http://www.technicaltrainingsolutions.c ... ions.shtml

http://www.technicaltrainingsolutions.c ... ions.shtml


. . . . .


I would strongly recommend a copy of the Wiring Regulations, and also (but not as strongly) copies of the Guidance Notes, but bear in mind there are new versions coming out in 2008, and not all of these are available just yet – pay close attention, and don't buy the 16th Edition versions by mistake.


http://www.amazon.co.uk/exec/obidos/ASIN/0863418449 or http://www.theiet.org/publishing/books/ ... dition.cfm


http://www.amazon.co.uk/exec/obidos/ASIN/0863418554

http://www.amazon.co.uk/exec/obidos/ASIN/0863418562

http://www.amazon.co.uk/exec/obidos/ASIN/0863418570 or http://www.theiet.org/publishing/books/ ... dition.cfm

http://www.amazon.co.uk/exec/obidos/ASIN/0863418589

http://www.amazon.co.uk/exec/obidos/ASIN/0852969937

http://www.amazon.co.uk/exec/obidos/ASIN/0863418600

http://www.amazon.co.uk/exec/obidos/ASIN/0863418619

http://www.amazon.co.uk/exec/obidos/ASIN/0863416160



http://www.amazon.co.uk/Electrical-Inst ... 0863415504 or http://www.theiet.org/publishing/books/ ... -guide.cfm



The Electrician's Guide shown above is a good explanation of the regs, but if you fancy one with a bit more of the electrical engineering theory behind it all, I can recommend this:

http://www.amazon.co.uk/exec/obidos/ASIN/0852962371 or http://www.theiet.org/publishing/books/ ... /19253.cfm

It is a commentary on the 16th, not the 17th, and the new one will be out soon, but if you can find a cheap second hand copy it will still be useful and informative, as the underlying theory never changes.


USEFUL WEBSITES

TLC Cable Calculator: here

Kevin Boone's Cable Selection Guide:here

Kevin Boone's Cable Calculator: here

Kevin Boone's useful basic guides:

http://www.kevinboone.com/electricity.html
http://www.kevinboone.com/domesticinstallations.html

(Disclaimer - I am not Kevin Boone, nor am I in love with him - I just found his site one time and thought it was pretty useful).


THE LAW

If you're in England or Wales you do need to know this:

http://www.ultimatehandyman.co.uk/forum ... t6296.html[/quote]

_________________


I'm sorry - I can't come in to work today, the voices are telling me to stay at home and clean the guns.

.

Dude...

_________________
Kind Regards,

Dan Robinson - http://www.jenningsheating.co.uk

If you give’m choices they'll give you grief.