Power in lighting problem

[dk1uk]

Hi - today I have replaced 3 ceiling pendant lights in the kitchen. They are all connected to a dimmer switch.

They look great but they don’t work! I got my multimeter out and found something that to me is strange so wondered if someone can help.

At the first light on the chain, there are two brown wires from the ceiling, one from the switch and another that takes the live to the next light in the chain. Both brown wires are in the same terminal, fair enough. However when I checked for power there, I get no reading BUT when I separate those brown wires from each other I get a normal reading on the wire coming from the switch.

I’m baffled - why would I get no reading when those wires are joined together in the same terminal?

Many thanks

 

[terryplumb]

What "readings" are you talking about?
Are you measuring voltage ? If so ,where are you taking measurements from ( between which two points )?

 

[Robster_1981]

look up Potential Difference. If you have two wires into the same terminal, you won’t get a voltage. Try putting your other probe on the neutral or Earth terminal and you should see 230v. Hope that helps

 

[dk1uk]

What "readings" are you talking about?
Are you measuring voltage ? If so ,where are you taking measurements from ( between which two points )?

Yes measuring voltage. I am taking one measurement from the light switch on the wall and another at ceil rose. It’s at the ceiling rose that I’m getting 0 but only when the two brown wires are touching each other.

 

[dk1uk]

look up Potential Difference. If you have two wires into the same terminal, you won’t get a voltage. Try putting your other probe on the neutral or Earth terminal and you should see 230v. Hope that helps

Thanks but my bigger concern is why the lights aren’t working - there is 0 voltage reading hence the lights aren’t coming on.

 

[Robster_1981]

Thanks but my bigger concern is why the lights aren’t working - there is 0 voltage reading hence the lights aren’t coming on.

We need more info really. When you are getting 0v at the ceiling rose, where exactly do you have the two probes?

 

[terryplumb]

Take a pic and post here ,of all conductors present at the first pendant.
As robster says above ,we need more info.

 

[dk1uk]

We need more info really. When you are getting 0v at the ceiling rose, where exactly do you have the two probes?

Thanks - on the ceiling rose, I have one probe on the live terminal (where the two live wires are) and the other on the neural terminal. When I take the brown wires out of the terminal, I get a normal voltage reading form the wire that goes back to the light switch. But, if I twist both brown wires together, I get 0.

 

[dk1uk]

Take a pic and post here ,of all conductors present at the first pendant.
As robster says above ,we need more info.

Will post tomorrow, wife is out and I need someone to take the weight of the lamp before I unscrew it from the ceiling.

 

[Robster_1981]

If it’s a loop in ceiling rose, then you might have the loop and switch lives together, which would explain why they don’t work. Can’t really be sure until we see more.

 

[dk1uk]

If it’s a loop in ceiling rose, then you might have the loop and switch lives together, which would explain why they don’t work. Can’t really be sure until we see more.

OK, I will post a pic in the morning. If it helps, at the first pendant there are two cables coming from the ceiling, same at the second pendant, then at the last pendant there’s only one cable, so I’m assuming it’s daisy chained. It’s a new build house, I didn’t touch the wiring in the ceiling roses, other than to replace the the live/neutral wires from the old to the new lamps.

 

[Robster_1981]

That all sounds right and that you’ve done everything correctly. If everything worked before, just try putting one of your old fittings back and see what happens. It could be that your new one’s are not compatible with a dimmer?

 

[dk1uk]

That all sounds right and that you’ve done everything correctly. If everything worked before, just try putting one of your old fittings back and see what happens. It could be that your new one’s are not compatible with a dimmer?

I don’t know if the old ones ever worked as only moved in recently and didn’t ever put bulbs in them as was always planning on replacing them. I did buy dimmable bulbs, but yes good idea I’ll try replacing new with old and see what happens. I’ll also try removing the daisy wires from pendant one and see if that makes pendant one work. Thank you.

 

[terryplumb]

If you don't know whether the old fittings worked ,putting one back isn't going to establish much.
If you have 240 volts live to neutral at the rose ,and your new fittings live and neutral conductors are connected to those respectively ,then the light should come on. If it doesn't ,the fitting and bulb/s are suspect. What exactly is the fitting / bulbs ? Are they LED' s , 240 volt ?

 

[Robster_1981]

So it’s a new build, but has had a previous owner? Maybe they’ve been DIY’ing. You’ve got power there of some description, so I’m sure it’s something simple.
It does sound like your switched live is mixed up somewhere. Test all wires to Earth with the switch on, then again with it off. The one that switches is the one you want to connect to the light, then it’s a case of connecting the neutrals. The switch live could be a blue wire depending on how it’s done.