DIY Doctor UK DIY Forums

Hi all,

I hope someone can give me some advice :)

I have a faulty LED driver in my bathroom downlight setup, so I remove the first downlight in the series to check the wiring was connected. It looks like some of the wiring has come loose. There seems to be a rogue Neutral and earth wire from one of the electrical cables. All the 3 Line are connected to one terminal, but only two of the Neutral are terminated together.

Am I correct in thinking all 3 Neutral and all 3 Line should be terminated together, and connected to the LED Driver input? And the 3 Earth terminated together?

If I connect up the driver to the terminated blocks, the LED light just flashes.

Pictures attached

Thanks in advance for any help!

Simon

Although the output from a true driver should be wired in series, what you show is not a true driver, it is a simple 12 volt DC power supply, so output would likely be in parallel, also it looks like a MR16 unit with G5.3 connection, most the lamps I have used are marked 50 Hz so clearly designed for an AC supply not DC, although likely DC will work.

To convert a system using an electronic transformer to work with LED lamps, often the transformer has to be replaced with a toroidal lighting transformer as the former has a minimum output, but toroidal lighting transformer don't have a minimum output, however 12 volt lighting strips used for decoration often need a DC supply, so they need a 12 volt DC power supply often wrongly named a driver, better quality LED's often do need a proper driver often around 340 mA with variable voltage often 6 to 36 volt. It is all to common to find the wrong one fitted.

Some 12 volt MR16 replacement LED lamps are actually DC, often marked 10 - 30 volt, used in boats and caravans, however normally more expensive than the AC versions so you are unlikely to buy DC versions from your local shop.

Internet shopping you can get all sorts with even 230 volt G5.3 versions being sold, so one has to be very careful reading the description.

Output from the power supply is normally separated extra low voltage so there is not neutral, only the supply to the power supply has a neutral, depending on ceiling height in a bathroom you may have to use 12 volt, but if not, far better converting to GU10 and use 230 volt lamps, then no worries that lamp and power supply don't match.

Sorry missed [quote] There seems to be a rogue Neutral and earth wire from one of the electrical cables. All the 3 Line are connected to one terminal, but only two of the Neutral are terminated together.
[/quote]
What you have is normal, of the three black cables two are neutral and one is switched line and the red sleeve has fallen off it.

Thanks for such a detailed response!

The DC power supply has been working in that setup for over a year, and only cut out the other day. It's when I removed the light to check that I saw the wires had come loose. So i'm unsure how the L/N on the DC supply input should be connected to the line/neutral and/or switched line.

I checked the LED lamps and they are 12V.