What have i done???

[securespark]

¦---------¦---------------¦---------------------------Neutral

¦---------¦---------------¦---------------------------Live

Imagine lamps in the three gaps (OK, I'm carp at graphics... )

Imagine the circuit is energised. Now break the neutrals at the right hand position.

The leccy will shoot down the live conductor, through the lamp(s) and appear on the end of the neutral wire you have just broken.

It's not really a neutral anymore, as it is disconnected from the neutral terminal when you broke the neutral connection at that point.

While I was busy posting this pathetic excuse of a reply, Col beat me to it with far superior stuff...

 

[thomo27]

thomo that won't work to id the switch wire.. it's possible to "see" 240V through the neutral that is disconnected as it will feed through the next light on the circuit back up the neutral..

so you would get 2 black wires showing at 240V..

the safest way is to do it with the power off and use the continuity or low ohms setting....

I experimented with this method today and agree that the safest and best way to test is to use continuity

I opened up the switch and connected the SL to the PL and then tested at the ceiling rose , is there any reason why you wouldnt connect the SL to earth at the switch and then test between E and the SL at the ceiling rose ?

 

[ColJack]

kind of daft to open the switch up.. why not just switch it on? unless you suspect a broken switch?

although in theory, could you still read continuity through a lamp downstream also? it would be a higher reading than from the "Loop" terminal through the switch back on the black wire...

 

[thomo27]

kind of daft to open the switch up.. why not just switch it on? unless you suspect a broken switch?

although in theory, could you still read continuity through a lamp downstream also? it would be a higher reading than from the "Loop" terminal through the switch back on the black wire...

but to test continuity wouldnt I need to connect the probes at each end of the cable , If I had a long test lead I would put 1 end on the SL at the switch and another on the SL at the ceiling rose..as I dont then I linked the 2 together at the switch and then tested at the ceiling rose..

Im most likely missing something really simple here and as a result making things hard for myself...

thanks again

 

[RF Lighting]

You put the probes onto one set of red and black wires at the ceiling rose end.

Switching the switch on will cause the tester to beep. Switching it back off will stop it again.

Thats the wire to your switch.

If the tester doesn't beep, try another set of red and black until you get the right ones.

 

[ColJack]

as the 3 red wires are in the loop terminal, then the red that you connect to the switch wire at the switch is already there.. switching th switch on connects it to the black switch wire.. no need to connect them together.. that's what the switch does..

 

[ban-all-sheds]

Im most likely missing something really simple here and as a result making things hard for myself...

What you seem to be missing is any kind of understanding of what a switch does.

Which is kinda worrying if you're doing electrical work....

 

[thomo27]

Im most likely missing something really simple here and as a result making things hard for myself...

What you seem to be missing is any kind of understanding of what a switch does.

Which is kinda worrying if you're doing electrical work....

I understand how a switch works I just wasn't familiar with testing for continuity in that way..

 

[ban-all-sheds]

I understand how a switch works

Then why did you think you had to take the switch off the wall and link the terminals together?

 

[thomo27]

To test for continuity however I overlooked that turning the switch on would do the same thing -

I understand how a switch works I simply didnt put this into my thought process when looking to test for continuity

 

[ColJack]

it's easy enough to have a brain fart when you're thinking too deep into a problem and overlook the easy solutions..