Lighting and Switches

[MasterAbacus]

While in the Loft today I found a Red Cable, with bare Wires, Well Several Actually.... My Horror.....

Traced one back this evening to source, and it run to a Light switch in the Bedroom, but wasnt connected, the earth wire that ran with it was connected to back box tho....

What im wanting to know it the Switch has a single wire in one hole ( I assume thats the feed to bedroom light, as the other Hole has two red wires in it, I assum to be the Mains ring for the lighting??

Please correct me if im wrong...

After some checking of the Light roses, the Nutral ( Black wires seem to run on a loop from Light to light... Is this normal?

In addition could i tap into the black ring (Spur like) coonect the red wire to the Switch and use the EArth and red, and the tap into black wires to add a Light in my loft, ??? Id like this to be a perminant thing... especially As i must check out the Several other Random Red wires up there..... would be easier with a light than a torch....

 

[ban-all-sheds]

1) You should stop assuming what wires and cables are for, and determine what they actually do.

2) From what you've described you've got nothing unusual - it's common for lighting circuits to loop from rose to rose with just the live going to switches.

3) Beware - in lighting circuits blacks are not necessarily neutral. And it's not a ring, BTW. You should look at the diagrams in the For Reference section.

4) A multimeter would be a useful purchase....

 

[MasterAbacus]

Ive had a look at the reference section, but nothing seems to be as mine are setup up.....

All the Wires in my Switches are RED, and the Black (Negs) run in a loop from Light to light....., then i assume end somewhere along the chain...

The house looks like it had a rewire within the past fwe years or so.... Cant confirm this tho......

Does it sound normal....

 

[SwindonSpark]

Yes it sounds normal. Happy now?

As B-A-S says, stop assuming and go and check!

 

[MasterAbacus]

Yeah Happy, But can i just add a new light to the Curcuit, by adding a double switch, and taking a feed from inside the common in the switch currently in situ....

Then for the NEgs and EArths just TAP into the Existing curuit somehwere????


Cheers for your help guys......

 

[breezer]

no, look in for refernce to see how it should be done

 

[SwindonSpark]

MasterAbacus wrote:
Then for the NEgs and EArths just TAP into the Existing curuit somehwere????

You don't really know what you're doing, do you?

 

[breezer]

its safe to say that is an understatement

 

[MasterAbacus]

Im no sparky, but ill have a go..... Ive just not seen a lighting curcuit like this before.....

This is why i thught it best to ask on here prior to just diving in....

 

[ban-all-sheds]

Ive had a look at the reference section, but nothing seems to be as mine are setup up.....

All the Wires in my Switches are RED, and the Black (Negs) run in a loop from Light to light....., then i assume end somewhere along the chain..

Apart from the use of red/red switch cables instead of red/black, you're describing what is shown in the first diagram on p1 of the For Reference topic...

 

[ban-all-sheds]

1) Showing how the basic lighting circuit cable loops from one ceiling rose to the next using 3 terminals (L, N, E):

2) Showing how a cable runs from the "loop" terminal in the rose (i.e. the permanent live) to the switch, and back to the 4th terminal in the rose. This return wire is the switched live.

Note the earth conection is not shown - this should also go to the switch position, and be connected to the earth terminal on the back box or the faceplate of the switch if it's metal.


3) So now at the rose there is a circuit neutral and a switched live, and connecting the light to those means that it can be turned on and off with the switch:

General advice: You seem to know nothing, or very little, about electrics. I would strongly suggest that you get some books and learn about it, as you'll be much better off doing things on the basis of understanding what's going on rather than blindly following a series of "connect the red wire to terminal 1" instructions with no idea why.

This is my list of recommended publications:- you should certainly get the first two on the list:

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

http://www.amazon.co.uk/exec/obidos/ASIN/0852028172

http://www.amazon.co.uk/exec/obidos/ASIN/0863413749

or http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 261

http://www.amazon.co.uk/exec/obidos/ASIN/0953788539

or http://www.tlc-direct.co.uk/Main_Index/Electricians_Guide_Book/index.html

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 234

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 235

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 236

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 237

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 238

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 239

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 240

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 250

http://www.iee.org/Publish/Books/WireAssoc/index.cfm?book=WR 500


The Electricians 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.iee.org/Publish/Books/WireAssoc/index.cfm?book=NS 031

You should also buy a multimeter....

 

[MasterAbacus]

WOW, Thanks B-A-L, you took some time to put that together for me.

I do understand the images you have shown to me, the "Loop" wires on my Lighting Curcuit are Black tho, not red. Thats the bit i dont understand.

I can see the books coming in handy, off to Amazon i go right now.

Ive already got a Multi Meter and will be checking things prior to doing anything anyways. Im only going on what i can see, as ive not really done much in this house electrics as yet. Testing wise anyway.

 

[plugwash]

I do understand the images you have shown to me, the "Loop" wires on my Lighting Curcuit are Black tho, not red. Thats the bit i dont understand.

colors are only there to guide humans working on a system they don't effect how the electricity actually flows through it

twin red cable is availible and is sometimes used for the switch drops however more normal is to just use standard red/black cable. The black core of this cable should be marked with red tape or sleeving to indicate that its a live but in the real world it frequency isn't.

(replace red with brown and black with blue in the above descriptions if using the new harmonised cable)