LED replacement for 4 foot tubes

[Ole Anderson]

I know we have a few lighting experts here and a few more of you with experience replacing 4 foot fluorescent tubes with equivalent LED tubes. I have been tasked with updating about 40 four tube troffers in our church basement and miscellaneous rooms (but not the sanctuary which has custom incandescent fixtures, which is another story). Many date back 35 years and folks are getting tired of switching out tubes only to find that the issue is with the ballasts. It has been suggested (possibly by me...) that we ought to consider bypassing the ballasts and popping in LED bulbs so we can be done with the ballast issues. Many manufacturers are coming out with replacement LED bulbs and the price is dropping fast. So, what has been your experience and what, if any, bulbs would you recommend?

As one example, I see HD has Phillips cool white 17 watt, 2100 lumens, 36,000 hour life at $6.18 each. http://www.homedepot.com/p/Philips-4...6590/206402867 Is the pin spacing on a T8 same at the T12's now in place?

[Dennis Heskett]

I know we have a few lighting experts here and a few more of you with experience replacing 4 foot fluorescent tubes with equivalent LED tubes. I have been tasked with updating about 40 four tube troffers in our church basement and miscellaneous rooms (but not the sanctuary which has custom incandescent fixtures, which is another story). Many date back 35 years and folks are getting tired of switching out tubes only to find that the issue is with the ballasts. It has been suggested (possibly by me...) that we ought to consider bypassing the ballasts and popping in LED bulbs so we can be done with the ballast issues. Many manufacturers are coming out with replacement LED bulbs and the price is dropping fast. So, what has been your experience and what, if any, bulbs would you recommend?

As one example, I see HD has Phillips cool white 17 watt, 2100 lumens, 36,000 hour life at $6.18 each. http://www.homedepot.com/p/Philips-4...6590/206402867 Is the pin spacing on a T8 same at the T12's now in place?

I bought mine from earthled.com. I did my garage. Was fairly simple, cut wires, remove ballasts and install. Directions were clear. I used the daylight type and they really brightened up my shop area.

[Greg R Bradley]

Converting T-12 to direct LED is easiest as they already have non-shunted tombstones. Most T-8 have shunted tombstones so you need to cut the shunt, if possible, or replace the tombstone. Everything in mounting and spacing is the same T-12 vs T-8 except the bulb diameter, which means the T-8 tombstones can be shorter or even really short. So as long as you are using the same diameter or smaller, everything fits.
You do realize that 36,000 hour life means that it would be easy to buy T-8 florescents that may last the same or even longer, right? T-12 have a much shorter life and use more power. So, existing T-12 should basically all be converted to T-8 or T-8 LED and LED is going to make the most sense at this point. Just don't fall into the trap that these are a permanent fix and will never need bulbs again.
For the on/off and occasional use I imagine those will see, LED will be the way to go and the ones you found will be fine. They will be a lot more directional so if the ceiling is low and they aren't troffers or wraps with something to spread the light out, it could be more uneven lighting.

[Pat Barry]

Converting T-12 to direct LED is easiest as they already have non-shunted tombstones. Most T-8 have shunted tombstones so you need to cut the shunt, if possible, or replace the tombstone. Everything in mounting and spacing is the same T-12 vs T-8 except the bulb diameter, which means the T-8 tombstones can be shorter or even really short. So as long as you are using the same diameter or smaller, everything fits.
You do realize that 36,000 hour life means that it would be easy to buy T-8 florescents that will last the same or even longer, right? T-12 have a much shorter life and use more power. So, existing T-12 should basically all be converted to T-8 or T-8 LED and LED is going to make the most sense at this point.
For the on/off and occasional use I imagine those will see, LED will be the way to go and the ones you found will be fine. They will be a lot more directional so if the ceiling is low and they aren't troffers or wraps with something to spread the light out, it could be more uneven lighting.

What is a tombstone in a flourescent light fixture? How do you identify it, how do you change it?

[Greg R Bradley]

The tombstone is the plastic piece that holds each end of the tube"
https://www.amazon.com/LEDwholesaler.../dp/B00DZIGJX6
Sometimes held in with one screw but normally slid in a slot and held in by the end cover, usually held in with two screws.
Usually only a pain to change in a few troffers or when someone has bolted a row of lights together so you have to do extra work to take the ends off.

[Chris Padilla]

And what is the shunt?

[Matt Marsh]

Ole,

I am the lead electrician at a University here in Northern MN. We've done literally 100s of retros here on campus in recent years. The biggest downfall with LED retrofit tubes is that they are directional in design (cut-off), whereas a fluorescent tube casts the light out in a 360° pattern. This is more of an issue in fixtures that utilize a reflector of some sort. In a troffer style fixture, the resulting light will often appear dimmer and actually offer less light. At typically $15 per tube for LEDs, versus around $115 for a LED troffer, we've had much better luck with just replacing the entire fixture with one of the low cost LED troffers, such as the RAB SWISH models. You might also check with the local utility, most of them offer a better rebate when the retro involves a complete fixture replacement, versus just replacing the bulbs.

Here, the rebates are $.75 per watt saved for hard-wired retros, versus $.20 per watt saved for bulbs.

[Matt Day]

I've done some limited research on this and 2100 lumens is not very high. If you're looking for more light you may want to look elsewhere.

[Ole Anderson]

Greg, thanks for the T8 to T12 comparison. All of our lights have old style T12 bulbs with non-electronic ballasts. The Sylvania T8 bulbs I referenced appear to be a retrofit style with the ballast in place, which requires a fairly up to date ballast, which we do not have. So I need to look around more to find the style that works off straight 120 volts. Our usage is probably in the neighborhood of 10-20 hours per week, large basement, less; offices, more. Most bulbs are well past their half life, so we already are below the peak lumens of new bulbs. Matt Day, as far a lumens, 2100 is in the ballpark of a single T-8 32 watt standard fluorescent. Each troffer has 4 bulbs so that would be 8400 lumens per fixture, when new. Matt Marsh, thanks for the reminder on possible energy rebates. All bulbs are in a troffer with a cracked glass style of diffuser, so as long as we point the bulbs down, we should be good. We will certainly do a test before embarking on a wholesale replacement program.

[Matt Marsh]

Ole, it is actually the troffers that suffer the most. You'd be surprised how much they use the white back of the inside of the fixture. The LED tubes in the photo below are in my office, the fluorescent tubes are in the identical fixture in an adjacent room. Look at how much light is reflecting off the back of the fluorescent compared to the LED. Granted they are Parabolic diffusers, not cracked glass styles, but you can still see the obvious difference.

LEDtroff.jpg
LED


Fluortroff.jpg
Fluorescent

[Wade Lippman]

If I can take advantage of this thread...
I have some 4' 1.5" diameter fixtures that turn on with difficulty, even after replacing the bulbs with ones that work fine in other fixtures.
I have T12, right? The ballast is failing, right?

So I can wire out the ballasts and use LED bulbs; is that correct? I don't have to do anything to the tombstones?
How do i wire out the ballast? Just cut two wires going to the ballast and connect them? Is it that simple?

I have some nice fixtures and replacing them is not a great option.

Thanks.

[Jason Roehl]

If I can take advantage of this thread...
I have some 4' 1.5" diameter fixtures that turn on with difficulty, even after replacing the bulbs with ones that work fine in other fixtures.
I have T12, right? The ballast is failing, right?

So I can wire out the ballasts and use LED bulbs; is that correct? I don't have to do anything to the tombstones?
How do i wire out the ballast? Just cut two wires going to the ballast and connect them? Is it that simple?

I have some nice fixtures and replacing them is not a great option.

Thanks.

The '12' in T12 refers to the number of eighths of an inch of diameter to the lamp. So a T12 lamp is 1.5" diameter, and a T8 is 1" diameter.

[Matt McCoy]

If I can take advantage of this thread...
I have some 4' 1.5" diameter fixtures that turn on with difficulty, even after replacing the bulbs with ones that work fine in other fixtures.
I have T12, right? The ballast is failing, right?

So I can wire out the ballasts and use LED bulbs

Yes, but depends on the LED tube you use.

I don't have to do anything to the tombstones?

It depends and the tube, current ballast wiring configuration, and if it's a single or double-ended installation. Here's a quick guide from the manufacturer I used:

https://hyperikon.com/wp-content/uploads/2016/04/Single-ended-Installation-Guide-Advanced.pdf

How do i wire out the ballast? Just cut two wires going to the ballast and connect them? Is it that simple?

In some cases. I was simply able to just bypass the ballast. I would consult the manufacturer's installation instructions when you decide on the product you need.

I have some nice fixtures and replacing them is not a great option.

Thanks.

Hey Wade,

Sounds like you have a T12 fixture and the ballast is probably on its way out. I inserted above what I learned replacing the lights in my shop. I'm no expert, but hope it gets you started in the right direction. There are several good threads on SMC worth reading.

[Bob Coates]

Ole,
The link you show to HD are for bulbs that leave the ballast in place. I have always found bulbs that don't require the ballast. That makes more sense to me since the ballast always goes also. I have done 4 and 8'. I found that some times you need to replace the tombstones to get the led's to work. Check Matt's post for good references to one end or both ends powered. Also when I replace with leds, I mark the fixture that it has led. and if single end power, mark that also.

Bob

[Jim Becker]

I use the replacements from Costco...great price and plug-n-play into existing fixtures. Direct wire are certainly less expensive, however, if you are up to the work of converting the fixtures.