Can work out why my new light isnt turning on!

[PrenticeBoyofDerry]

I measure 240v between the live loop and black wire no 2 and very low voltage (circa 5v) between the live loop and the other two blacks.

240V does that then reduce to near zero when switch is opened?
Edit this, incorrect info given!

Black wire number 2, sounds like neutral wire, the other two if tested to earth and switched on/off what results do you get?
And testing number 2 to earth what results then?

 

[Yukster]

Need clarification on
* Number in total of black conductors
* If you are referring to them as number 1,2,3...... etc. Need to know which are live when switched, which are not and if unswitched how those results change. As you stated number 2 was at 240V and the other were at 5V, but then stated number 3 was reading 240V!

3 black wires/conductors
i measure 240v between the live loop and black no 2 when the switch is on and when it's off
I measure 240v between earth and black wires no 1 and no 3 when the light switch is on and 240v between earth and black wire no 3 when the light switch is off. no voltage between earth and black wire no 2
I measure 240v between live loop and earth regardless

 

[PrenticeBoyofDerry]

3 black wires/conductors
i measure 240v between the live loop and black no 2 when the switch is on and when it's off

Suggests that is neutral

I measure 240v between earth and black wires no 1 and no 3 when the light switch is on and 240v between earth and black wire no 3 when the light switch is off.

That would suggest that black no 3 is permanently live and black 1 is switched live, if this reads 0V when switched off.

no voltage between earth and black wire no 2

Again suggest that is neutral

I measure 240v between live loop and earth regardless

expected

For the minute I suggest putting black no 3 (perm live) in a connector of it's own. Then connect black no 1 to live side of lamp and black no 2 to neutral side of lamp.
And see what happens! with regards to switching and power.
I find it strange that you have this black no 3 permanently live! A little further investigation would be required to determine the reason behind this!

 

[Stevos]

I find it strange that you have this black no 3 permanently live! A little further investigation would be required to determine the reason behind this!

I wonder if that "permanently" live black is actually a switch wire from another location? I'm thinking part of an old setup for some kind of crossover or multi-way switching thing that may now be unused, partly dismantled, or hidden. Or maybe an old switch cable from another location that wasn't disconnected when it was replaced with the current switch.

Admittedly I don't know what I'm talking about, but it sounds like something is a bit odd with that wiring.

 

[PrenticeBoyofDerry]

I wonder if that "permanently" live black is actually a switch wire from another location? I'm thinking part of an old setup for some kind of crossover or multi-way switching thing that may now be unused, partly dismantled, or hidden. Or maybe an old switch cable from another location that wasn't disconnected when it was replaced with the current switch.

Those are similar thoughts to mine, maybe it was switched from different location. Was hoping that once the light was functioning correctly, then investigating the conductors at the live loop, may allow this conductor to be made redundant and isolated.

 

[Yukster]

Thank you all for your advice. The light fixing is wired correctly now but I also had to sand the contacts in the lightbulb socket to make it work. Problem solved

Untitled

• Yukster
• 26 Feb 2014
• 1

 

[Taylortwocities]

Great!

Which solution worked?

 

[Stevos]

It could be worthwhile finding out what's the deal with your permanently live black wire (#3?).

Particularly with it being near a shower, strange wiring might be something to be concerned about.

What did you end up connecting this wire to?

 

[Yukster]

My multimeter packed up so I'll remeasure it when I get the new one delivered hopefully tomorrow

 

[WabbitPoo]

Thank you all for your advice. The light fixing is wired correctly now but I also had to sand the contacts in the lightbulb socket to make it work. Problem solved

Untitled

• Yukster
• 26 Feb 2014
• 1

Its a shame that, after all that work, it looks like a light you'd find in a prison block!

Still, happy that you got it sorted