UK Power for LED 18-20 metre stretch

[Juney]

Hi, I’m hoping someone can enlighten me. We want to put LED lights around the picture rail in our lounge. There would be around 16-18 metres of lights, and I have purchased 2 x 10 metre of 12v 120 LEDs per metre. In hindsight, and having read up a bit more, I’d have been better to buy 24v. Anyway, I need a power supply, but realise I won’t be able to power 10 metres without a voltage drop. My brother has some power supply/drivers he will give me which are 220-240VAC 50/60Hz Output 12vDC max 2.5A max 30W and has 10 of them. Will they be right for my setup, and how should I attach them? I did read that you can connect the power to each end of the light strip and so power from both ends. Any help very much appreciated

 

[DefyG]

Some idea of the wattage of the LED strip help eg. w/m or total.

 

[Juney]

Some idea of the wattage of the LED strip help eg. w/m or total.

It says 10W per metre, which is a bit scary if that means each of my 10 metre strips are 100W so we will be using 200W all evening - that can’t be right for low voltage lighting surely?

 

[DefyG]

Assuming this is secondary lighting, I think they will be much too bright for the application what is the luminous output? (what colour are they (3000k, 4000k ??)

Its 200w at 12v not 200w at 230v.

 

[Juney]

Assuming this is secondary lighting, I think they will be much too bright for the application what is the luminous output? (what colour are they (3000k, 4000k ??)

Its 200w at 12v not 200w at 230v.

Thank goodness for that! They are secondary lighting and I hoped they wouldn’t be too bright They are 6500k cool white! Maybe I’ll be glad of a voltage drop!

 

[Juney]

Thank goodness for that! They are secondary lighting and I hoped they wouldn’t be too bright They are 6500k cool white! Maybe I’ll be glad of a voltage drop!

Forgot to say they are going behind diffusers

 

[DefyG]

6500k is more 'Daylight' than Cool White and diffusers wont dampen it down much if clear or frosted.

Volt drop wont necessarily cause the whole strip to 'dim' as you would still have 12v near the source so full brightness and 9v (say) at farthest point so not full brightness more of a graduated dimming along the length!

 

[littlespark]

Where are the power supplies going? You’ll need one every 3m, plus mains wiring to each.

The quality of LED tape can be varied so factor in future replacement in any plans.

 

[Juney]

6500k is more 'Daylight' than Cool White and diffusers wont dampen it down much if clear or frosted.

View attachment 123042

Volt drop wont necessarily cause the whole strip to 'dim' as you would still have 12v near the source so full brightness and 9v (say) at farthest point so not full brightness more of a graduated dimming along the length!

Looks like I need to think again then. Maybe I should have gone for warm white instead

 

[Juney]

Where are the power supplies going? You’ll need one every 3m, plus mains wiring to each.

The quality of LED tape can be varied so factor in future replacement in any plans.

We are in a bungalow, so the power supplies can go in the loft, but getting power every 3 metres would be difficult. I imagined we would put power in the corners of the room, and lights meet in the middle. The other option we have is to just have them along one wall and over the chimney breast, and power could come from each corner, but it’s not what I wanted really. So for ambient lighting, what would you suggest?

 

[Taylortwocities]

When connecting several lengths of LED tape together from a single power supply I have found that the lengths get dimmer as you get further from the power supply.
You’d need to try yours out but, if it’s a problem, I have solved it by wiring the strips as a ring. Ie run the power to both ends of the run.

 

[EalingBadger]

We are in a bungalow, so the power supplies can go in the loft, but getting power every 3 metres would be difficult. I imagined we would put power in the corners of the room, and lights meet in the middle. The other option we have is to just have them along one wall and over the chimney breast, and power could come from each corner, but it’s not what I wanted really. So for ambient lighting, what would you suggest?

Just a note of caution - the power supplies used for this kind of thing are typically not of the highest quality.

I have observed the aftermath of a number of them overheating or even bursting into flames.

Good ventilation for cooling purposes is essential.

I would be cautious as to how you place them in the loft and DEFINITELY do NOT cover them in any insulation.