LED Fluoresecent replacements ????

[newshound]

Andrew has some big toys!

[DerbyBorn]

I presume you have 3-Phase. Is the load spread across the phases?

[Andrew Mawson]

This is true - you've been looking :)

Total is something like 4000 sq foot

Andrew

[Andrew Mawson]

Yes, though when I installed it I wasn't too keen on doing that as the main bank of switches thus has 415v three phase in it - it's suitably labelled !

I'm lucky in that I have 160 amp per phase incoming with the 11 kV to 415 v transformer on the wife's vegetable patch so not much volt drop on load - in fact I've just had to have UK Power Networks change the tappings on the transformer as we were getting 257 volts over night !!!!!

Andrew

[jack]

Still a hell of a lot of lights in a space that big.

[Tim Lamb]

In message , jack writes

I have 16 twin 5' battens for a workshop 22'x45'

[Andrew Mawson]

OK Tim has 16 x 2 x 5 = 160 foot of lighting in 990 sq foot I have 72 x 6 = 432 foot of lighting in about 4000 sq foot

So I reckon that about the same density

Andrew

[jack]

Mad.

[Tim Lamb]

In message , Andrew Mawson writes

Measured with my ancient Sangamo Weston light meter this morning.

A bit over 150 Lumens/ft.2 at work bench height. Reading micrometers, vernier gauges etc. is fine.

Obviously task lighting could be used at a significant saving but detrimental to time spent.

[Dave Plowman (News)]

Undoubted?

I doubt it. The claimed incandescent equivalent is always pie in the sky. And even if they give a claimed output in lumens or whatever, they seem to be different lumens than the ones you get from incandescent.

It's almost as if they had used the very least efficient incandescent - like say an early carbon filament type - as their benchmark. Certainly not halogen.

[Dave Plowman (News)]

And not switching them on at all would save even more electricity. ;-)

Quoting input watts is a nonsense, unless they also give the light output. Accurately. Not something most makers do. They lie through their teeth - knowing it's not an easy thing to check.

[Dave Plowman (News)]

Over what type of florry tube? The very cheapest ones often have a poor quality of light - but you can buy decent ones. LEDs are usually restricted to so called white or warm white. And both have a poor spectrum of light - unlike decent florries. Which may be important in a workshop.

[Andrew Gabriel]

They are a little more efficient than T8/T5 linear fluorescents, but can be significantly more efficient when light is required to one side of the tube only (which is often the case) as you don't lose anything on the luminare/reflector efficiency. Where light output is downwards, you also lose less due to dust settling (and this becomes significant when there's a longer period between relamping and no routine cleaning in dusty environments).

LEDs win even more over compact fluorecents, because CFLs are not as efficient as linear tubes, and LEDs win very significantly in spot or flood lamp applications where CFLs are particularly poor and LEDs particularly good.

[Andrew Gabriel]

They are not significantly different. My concern would be how much longer they will be around. There is one company still developing them, but I see LEDs being fitted nowadays where metal halide would have been used in the past.

[dennis]

I would be more concerned with the strobe effect from florries and, possibly LEDs. You really want a constant light source next to any rotating machine.

Industrial units put alternate tubes on different phases to minimise the strobe and you used to get longer persistence tubes.

[The Natural Philosopher]

Total cobblers.

halide around 5%, Fluorescent about 20%.

[The Natural Philosopher]

Not seen any strobe on the LEDS I have installed this last year. Suspect its either a very HF inverter, or its smoothed, or both.

[Andrew Gabriel]

Strange units, but that's around 1500 lux. That's the same I have on my electronics workbench, which is done with twin 5' tubes suspended about 1m over the bench with DSE reflectors. (Dirt cheap tubes - could probably do better with better quality ones.)

Yes. You should nevertheless avoid having work areas with more than

10x the lux of adjacent areas, so at 1500 lux task lighting, the room lighting should still maintain 150 lux minimum (and scale up for higher level task lighting).

[Dave Plowman (News)]

You really shouldn't be using mains frequency florries in this day and age. High frequency ballasts are far more efficient, as well as running at a frequency where strobing isn't a problem.

[Dave Plowman (News)]

You'd need a very interesting combination of LEDs to get the same even light that florries with a decent reflector gives?

Are you saying LEDs can't get dirty? ;-)