Wiring problem with downlights (Australia)

[tombsc]

Hi all,

I have recently added two new 12v 35w halogens into the existing circuit in the bathroom. 1 of the new lights went off after about 30mins. I have replaced the transformer and the same thing happened.

My diagram (sorry it isn't great!) shows what I have done. The bit in the yellow box is what I added. Everything else was there already and working fine. I know it may look like I have joined lives to neutrals but that's just my poor drawing skills, all lives are joined to lives and neutrals to neutrals. There is no earth connection.
I believe the power must be coming from the switch, so these are all kind of like a chain of spurs. My entire light circuit is like this.

Any idea what is wrong?

Thanks

Untitled

• tombsc
• 3 Mar 2013
• 1

 

[ericmark]

Everything you show seems fine but this is a UK forum and we likely do things a little different here. There is a Non UK section maybe the Sysops will move this post?

But really you need to find a local forum.

 

[tombsc]

Thanks for the reply. Sorry this is in the wrong forum I didn't realise there were others.

We don't really have similar forums here, there isn't much of a DIY scene to be honest but in refuse to pay an electrician for something that should be so simple.

Happy for this to be moved to the other forum but I'd assume electricity is the same wherever you are, just the circuit arrangement that's different.
I'm on my phone and typing quick so sorry for the typos.

 

[ericmark]

In the UK we feed the power to first lamp and daisy chain lamp to lamp with the supply. Each lamp has 4 connections Switched Line, Supply Line, Neutral and earth and the switch for each lamp is supplied from the ceiling rose which is a junction box as well as a ceiling attachment. Because the distance lamp to lamp is less than switch to switch as it does not have to go up and down the wall the last lamp in the circuit has a better loop impedance than when wiring switch to switch.

I have looked at USA sites and it seems they wire switch to switch and also use different colours to us.

I know you have some strict rules where you live even worst to our Part P about doing DIY and so can understand why no local forums.

But where colours and routes could vary to our system and not even sure on voltage we really could give out a load of bad advice.

In the UK we are moving away from quartz lamps and it is causing a lot of problems as the so called transformer is not really a simple transformer but an inverter which means it has both a minimum and maximum rating so to fit LED lamps into an extra low voltage (12v) system often means also changing the so called transformer.

So we are moving to low voltage (230v) lamps like the GU10 where one can easy swap between LED, Cold Cathode, and Quartz.

However we have strict rules for bathrooms with zones where we can fit 230v lamps and other where they have to be 12v.

Even our words may be different. Here 230vac is called low voltage and 12v is extra low voltage. We call the phase wire Line and both the phase wire and the neutral are called Live.

Our colours have changed brown is Line and Blue is Neutral we no longer use red and black.

So you tell me is our electric different to where you are?

Do check sizes of the transformers/inverters and check they do go down to 35W in this country often called VA so 35W nearly equals 35VA the difference is down to power factor and for what you are doing you can think of W = VA.

 

[tombsc]

Thanks for that. I'm actually British but been here 3 years now. When in the UK I rewired a lighting circuit so I understand the main differences, but regardless of wire colour, the way electricity works is still the same and that's why I'm stuck on this problem.
The transformers came with the lights so they are correctly rated, I'm just trying to figure out if I've done something that is causing the final transformer to fail. Could it be too many lights (and extractor fan) on one switch?
I'm really at a loss.
Our wiring is red= live, black=neutral, green=earth. Using 1.5mm twin core cable, max 1m between lights. 240volts circuit.
Could it just be bad luck and coincidence that I got 2 dodgy transformers and they both failed? Seems unlikely but possible I suppose.

 

[JohnD]

We don't know where the supply is coming from, and your sketch does not show us.

It might be interesting to see behind the light switch. Have you got a multimeter? If not, go to a hardware store and buy one.

 

[tombsc]

Behind the switch :

Untitled

• tombsc
• 3 Mar 2013
• 1

 

[ban-all-sheds]

We don't really have similar forums here, there isn't much of a DIY scene to be honest

Probably because DIY electrical work is basically completely illegal in Australia?

but in refuse to pay an electrician for something that should be so simple.

Not simple enough, it seems....

 

[tombsc]

We don't really have similar forums here, there isn't much of a DIY scene to be honest

Probably because DIY electrical work is basically completely illegal in Australia?

Ill be getting it checked out by an electrician once I have it all done.

but in refuse to pay an electrician for something that should be so simple.

Not simple enough, it seems....

Ha ha. But it should be!

 

[securespark]

What about the usual problems that beset "transformers" the world over?

Cheap ones failing prematurely, loft insulation causing overheating, ditto poor air circulation, limited space, etcetera....

Sure the tranny is correctly loaded? Can you post a piccy of one?