4' Led tubes

[thewizzard]

How does this all work? ... This lighting issue is changing rapidly and I just want to make the right decision.

Papa Jim

In modern times, the T8 and T12 lables refered to the 1" and 1.5" in diameter tube size.

At some point they added high efficiency and high-output bulbs, electronic balasts, high-efficiency electronic balasts, different wattage bulbs ........ and of course the old style magnetic balasts can still be found.

Forget all of this, its pretty much all obsolete now except bulb diameter and socket size if you currently need the high effeciency skinny tubes.

The new LED tubes that will eventually own the market run on normal 120 vAC house power. No balast needed. There are two different styles. One connects the two power wires to the two pins on one end of the bulb. The other connects one wire to either or both pins at opposite ends of the tube. The fixture gets the ground wire attached just like it should already be.

You keep your current fixture in place with whatever reflector or diffuser it may have, cut the wires off the old balast and leave it in place or toss it in the trash, then connect the 120 v supply wiring to the wires on the sockets ( often called tombstones ). Done, you now have a led light. You can use one or two bulbs in the fixture.

The LED tubes are brighter so if you use two of them in one fixture it will be much brighter than before. If you use one bulb, it will be a little dimmer than before.

There are also led bulbs that plug directly into an existing fixture that has a balast. If you have a functioning light, I'd say you are wasting money buying LED tubes to put into it. The energy efficiency of the LED tube is lost since you still need to drive the balast. Just use it as is until the balast fails then rip out the balast and set it up for 120 v LED tubes.

I have also started replacing the 8 foot tubes at work with 120 v LED tubes when the balasts fail. 

Also, pay attention to the overall reviews of the tubes that you buy. This is a very quickly growing segment of the industry and is going to have some bad players with junk products. And, don't be in too much of a hurry to run out and buy tubes because they are in vogue. The price is dropping rapidly. Wait until you need them.

[Papa Jim]

Thanks Wiz! Pirate's reply and sniper's reply left me a little confused but they both make sense once you know there are two different styles. I went back and looked at the schematic for the bulbs I ordered and it just shows (L) to one end of the bulb and (N) to the other. In old fart's language that's "'hook the black one to one end and the white one to the other", right? 

Papa Jim

[Strokes77]

I have 12 Sets of florescent lights in my shop.  I believe only 4 sets are working at the moment. I bought a huge box of bulbs and tried to replace them. Didn't work. I got frustrated and quit messing with them.

I don't know enough about them.  Is there a video or website I can go to that can explain the best way to replace them all with LED?

[yuri]

I still do not get why folks get so excited about LEDs. Please do not think that I am antiLED guy. I like them, they have their place, but that does not mean they always better choice. Most folks say LED are better then fluorescent light, either better efficiency and brighter. Where is than claim come from? Let see.

I have Litetronics T8 bulbs 5000K produce 3,200 lumens and have CRI 90

LED replacement bulb mentioned in first post produces 1800 lumens and CRI 80

or 22W from greenlightdepot -- 2200 lumens and CRI 75

So, quality of light from LED is significantly worse, and they generate 1.5-1.8 times less light output. How LED can be better?
I understand cool factor, but that is it. Please understand, I am not against LEDs, simply want to understand the true reason.

Probably manufacturers and sellers want to sell more and they just made every effort to assure you that it is absolutely necessary to replace your bulbs with new stuff.

[Robert Adams]

Direction of light throw has allot to do with it so comparing lumens from one to the other isn't a straight crossover. 

      I was also skeptical but when we started using them in commercial installs it was a no brainer. In real world use the led is a better product as the tech sheets can lie to you as they aren't directly comparable in all aspects. Also there seems to be allot of fibbing going on with light test results as well.

          However there are allot of bad leds out there. But the quality has been improving very very fast.

[bandsaw]

Fluorescent tubes get dimmer every day - it's stated in the light companies data. It's slow so you don't notice until you put in new tubes.

How much light output they have in later years is more important than when new - not new for long.

[yuri]

bandsaw,
you are right, they get dimmer, but anyway not that much. I quoted initial lumen output, but it has 2975 (mean) which still is significantly better.
You may be surprised, but LEDs get dimmer with life too! That is what are not told by LED sellers/manufacturers.

[thewizzard]

Lumen ratings from the manufacturer (max or average) can be misleading for many reasons. Aside from outright lies 
  the biggest one is probably what R. Adams mentioned above; light path.

Fluorescent tubes put out light in a 360° path around the tube and the total light output is the value quoted by the manufacturer. In the real world in a fixture with white reflector and plastic diffuser the useable output is much less. I've seen some people argue that as much as 66% of the light can be lost 


Most reflector type fixtures can't be this bad 
 A more realistic number that I have seen tossed around is about 33% loss. 

LED tubes put all their output into a half circle (or less depending on the design). You can toss them into a reflector type fixture but the reflector does't do anything since " 100% " of the light is thrown down. If you want to directly compare the lumen ratings of a fluorescent tube in an " average " fixture versus an LED tube measured underneath the fixture, you need to de-rate the listed fluorescent lumen value by about 1/3 (or more) due to reflector loss. So, an average 3000 lumen fluorescent tube is about equal to a 2000 lumen LED.

I've seen this myself, first hand, real life ... A single SGL 22 watt LED tube listed at 2,310 lumens (Amazon description) is brighter than two 32 watt GE or Philips bulbs in the cheapo mini reflector fixtures I have. I'm not claiming those bulbs are anything special; they are just what Home Depot had at the time I bought them.

As I said above, if you currently have a functioning fluorescent light just keep it as is. But, if the balast goes out I think you better off with a simple 120 v LED replacement tube and 3 minutes of wiring.

Fluorescent tubes have come a long way from the original Tesla tubes that GE started marketing back in the 40's and they have had a great run for 75 years but they will fade into obscurity just like rotary dial phone did 

[yuri]

I do not see affordable LEDs with good (~90 or better) CRI. All of them not more 80. Very important when it comes to finishing or any color related work.
OK, I stop at this point. You folks just love LEDs

[BloomingtonMike]

Whats the LED fixture/bulb output equiv to this high bay 6 Bulb T5 fixture with 54W T5HO bulbs? I am at $109 ea with bulbs.

http://www.wholesalecontractorsupply.com...oCZUXw_wcB