Is SELV cheaper to run than mains?

[--tom]

Is SELV cheaper to run than mains?

 

[JohnD]

no

 

[aptsys]

Maybe in terms of lamp life though.

 

[ban-all-sheds]

If you are concerned about running costs you should not be considering any form of incandescent lighting...

 

[ebee]

Well if you are running tungsten halogen lighting then SELV would be cheaper.

But the reason is not as simple as you may be thinking

 

[--tom]

thank you all for the info. So stay away from incan. use Halogen but expect to break even on costs, is that right?

 

[ban-all-sheds]

So stay away from incan. use Halogen

Good luck finding halogen lamps which are not incandescent.

 

[aptsys]

Halogen lamps are still incandescents. If you're worried about running costs, look at fluorescent and LED light sources. There are some decent LED fixtures emerging, but they are still expensive, so fluorescent lighting is likely to be your best bet. Anyone seen those 150W LED Street Lamps? The 50W LED emitters I have at home are also damn bright.

 

[ban-all-sheds]

I've got a 3-5mW LED device in my pocket - very bright. But quite a narrow beam...

 

[Steve]

Anyone seen those 150W LED Street Lamps?

You know, its a shame. Doncaster council have just spent millions replacing the streetlamps and posts and traffic signals along the A638, right through doncaster, about 5 miles in total, What did they fit? HPS lights and incandescent traffic lights. LED traffic lights have been around a few years now, why not use them? I guess it was hoping for too much for LED streetlamps though - given the cost.

 

[aptsys]

LED traffic lights have been around a few years now, why not use them?

I'm still not sure what their criteria is for using them. There is a large roundabout near my place of work that has recently had new traffic lights installed, yet there is a mix of LED and incandescent traffic lights

 

[sm1thson]

I've got a 3-5mW LED device in my pocket - very bright. But quite a narrow beam...

yep, but now leds + optics are around that give various field of views and can take a lot more than 5mw.

 

[ban-all-sheds]

Hmm.

Not much more than 5mW can damage eyesight, and it's not a huge step to the point where things catch fire...

 

[sm1thson]

Hmm.

Not much more than 5mW can damage eyesight, and it's not a huge step to the point where things catch fire...

this is why light (and sound) isnt measured in watts (other than by marketing people). in terms of a laser you would be right >5mw eye damage is an issue a 30mw laser can pop a ballon and you can feel it on your skin. but a laser is (generally) very focused.

For setting things on fire a 50w incan would be a far better tool than a 50w led even though the 50w led would be brighter -this is because the wasted energy comes out of the back of the led via conduction where as on an incan it comes out of the front by infrared and theres a lot more of it. so if you scale it down a 5mw incan will burn more than your 5mw LED, i dont think you need to worry much.

 

[ban-all-sheds]

I was joking.

And I know that LED lamps don't emit laser light.

Let's hope the people selling 200mW greens on eBay are joking too...

Mind you - a 50W mains powered laser would be pretty impressive. Maybe I could use it on the cat that thinks my flowerbeds are its toilet....