Any electricians who could give me a hint?

[yachtie10]

I am trying to get my pool light working and im having no luck

Pool light is 12 volt 30w led and came with installed sealed 2 core wire long enough to go back inside
The wiring for the old pool light is still there
I have installed a PDL cabinet (I had one lying around) and using a rcd that was in it to connect the phase (red) to the 60w transformer
The black neutral is connected to the other terminal on the transformer.

the earth wire is not used so connected to the bus in the cabinet (green)

Now when turned on can get voltage on 230 volt side but nothing on 12 volt side
tested multimeter on car battery and working fine
replaced transformer and same thing
conected to light and nothing
connected light to battery charger works fine

went to lighting shop and they said ive done it right and i get another transformer and same result

I am no expert on ac wiring so i wondered if I am doing something stupid (im very careful about isolating things while working)

any ideas?

[JustNick]

Are you using an isolating transformer and seeing 230 volts ac on inputs and outputs? do you have a regulator/rectifier unit in the circuit to cut the power down to 12 vdc?

[yachtie10]

Are you using an isolating transformer and seeing 230 volts ac on inputs and outputs? do you have a regulator/rectifier unit in the circuit to cut the power down to 12 vdc?

Im using a 60w lighting transformer (this was what was recomended by the light supplier)
230 on input nothing on output

Thats the only unit doing the stepdown

this is the new one
http://www.tridonicatco.com/VIPER/

[NinjaNanna]

Set your multimeter to AC and measure the output.

I suspect that this transformer only steps down the voltage and does not convert it to DC.

Most LED lamps require DC to operate (that's why it works on the car battery).

Another hint will be if the transformer outputs are marked with + / - or pos neg. If they aren't then you can be sure its an AC transformer.

[Virago]

Take the RCD out of the circuit and re-test.

If it's not that, it sounds like you've got the wrong transformer.

[avgas]

Its the wrong transformer I suspect. Or the right transformer - but you need to also buy a regulator as a separate unit.

That tranny mentions Vac and VA (ac power).....but nothing on Vdc.'
Your LED light unit will need a regulator if its doesn't have one already (which is why it works on the battery charger - they are Vdc).

[avgas]

if your still stuck on the weekend I am more than happy to give you a hand. I ain't reg'd.......but I have worked on light units when I was getting my engineering hours done.

[paturoa]

So you can see 230 ac volts on the input side to the transformer?

And see 0 dc volts on the out.

-is the tranny supposed to put out dc or ac?
- fuse or reset button in / on transformer?
- 230 wired to wrong side of transformer (ie you've wired 230 to the 12v output)?
- stuffed tranny?

Take it back to where you bought it and get them to check it.

[nadroj]

Light Emitting Diodes (LED's) are DC only and polarity conscious. Your 230VAC supply is converted into 12VDC unless it has a bridge rectifier built in or wired in the Low Voltage side of the transformer to convert it to 12Volt DC.
As suggested check the output voltage in AC range to confirm.
Only other likelihoods are low voltage polarity or the 230VAC wired wrong onto the transformer.

[nodrog]

http://images.cheezburger.com/completestore/2009/8/28/128959493897569493.jpg

[yachtie10]

thanks guys I think the issue is the transformer

yes i think it is ac to ac not DC like i should have

Discussed with shop and as a coincidence they did some testing on these transformers and LED lights and the electricians spent hours trying to figure out why a lot of combinations dont work

They didnt think DC was the issue but I think you guys are right

They gave me a better transformer to try. but I see that its still doesn't mention dc and I dont think it wil work
ill check it shortly

but I am at hampton downs for the next 3 days so wont be able to do anything about it anyway till monday.

will probably get back to it then and get the right transformer ordered.

[yachtie10]

well thats a surprise

Working now and still not getting a dc reading so must be ac
I guess the light is smart enough to handle it (It is a smart multicoloured light)

Thanks again
Your answers reminded me to ask the right questions again (never got a satisfactory answer when I originally bought the transformer)

All new outside lights done and dusted on to the next job

[avgas]

I guess the light is smart enough to handle it (It is a smart multicoloured light)
Great stuff. Yeah I figured 1 out of the 2 should have a regulator built in. But couldn't see it on that tranny info you gave to us.

Show us a pic of the pretty lights :)

I used to have a prick of a time designing those emergency exit lights you see everywhere. The lights used to be AC.......but then you had to charge the battery using DC and when the power dies (or someone hits the test switch) then run the lights on DC. And all the gear had to be mounted in those stupid boxes......and not catch on fire.

On another note, a charged but disconnected tranny can still shock you. damhik

[St_Gabriel]

On another note, a charged but disconnected tranny can still shock you. damhik

Is that what they call a "Reach around"?

[Katman]

any ideas?

nek minit...

[avgas]

Is that what they call a "Reach around"?
Yeah.
But that is nowhere as bad as a discharged tranny.