Linear T8 Fluorescent Tube Light Bulb replacement, switch to LED? - Page 1
Forum section: electronics / general

author: BlackICE
author_rank: Regular Contributor
timestamp: July 31, 2023, 02:37:23 am
content: I have a room with 16 fixtures with 3 tubes each of T8 48" 32 watts tubes. One of the fixtures was very rarely flicking, I never directly saw it but noticed flickering in the room. The fixture I think it is coming from is a little dimmer ~80% compared to the other 15 fixtures. I went to change the tubes and found it strange when I replaced the 3 tubes it didn't light up all the tubes. One was on, another was dim the 3rd was off. I was baffled and tried 3 more new tubes, same result. I restore the 2 of the older tubes, leaving one new one it and the fixture works fine. The 2 older tube have a different color and lower light output.Any opinions on why the fixtures won't light up with 3 new tubes, but did light up if I left 2 old tubes in? Is it the ballast?I'm in CA and soon fluorescent tube will be outlawed so I have to make a long term buy decision. Buy a number of replacement sets of tubes and ballasts, or transition to LED tubes instead. The LED tubes cost over 2 times more and their specs aren't that impressive. The lumen outputs are only 1800 compared to 2600 for the fluorescent tubes. Although the LED probably have more useful light pattern. Most of the 1800 lumens are directed downwards, whereas the fluorescent tubes have more than 1/2 there output in the wrong direction and are dependent on the reflections from fixture to direct the light downwards. The LED's lifespan is about 1.5 to 2 times longer than the fluorescent making up some of the cost differential. The lifespan of fluorescent fixture are pretty well know, IMO the lifespan of LED replacment tube is a big unknown. I tend not to believe spec on many products from companies I never heard of. Many made in China tubes lower in cost or buy brand names at a higher price hoping they did real lifespan testing.If switching to LEDs is is better to get the universal type that can work with or without a ballast, or remove the ballast and run LED tube designed to run only without a ballast. Of course the choice without ballast is more labor. These fixtures are 14 feet in the air so somewhat of a PITA to work on.This is what I brought,https://www.grainger.com/product/56GK79?RIID=16971797

author: edtyler
author_rank: Contributor
timestamp: July 31, 2023, 03:08:34 am
content: I have the same concerns living in the Peoples Republic of Kalifornia. In addition, as an Amateur radio operator, RF noise by Chinesium electronics is a very real concern.If anyone have a suggestion for high quality, low RF replacements for 8 foot T12 HO bulbs/fixtures, it would be appreciated.

author: edavid
author_rank: Super Contributor
timestamp: July 31, 2023, 04:31:04 am
content: Do you have 3 tubes per ballast? I am not surprised you are seeing some strange behavior with that configuration.Anyway, I went through this in 2017 and I found that the no-ballast LED tubes I could buy would require replacing the tombstones in the fixtures. Also, the ones I tried were annoying slow to turn on. Therefore I went with the ballast required type, which didn't require any fixture changes, and turned on faster. I bought some cheap Utilitech tubes rated at 2000 lumens and 4000K, and they seem much brighter than the Philips 3000 lumen 3500K fluorescents that they replaced. None of them have failed to date.

author: BlackICE
author_rank: Regular Contributor
timestamp: July 31, 2023, 05:08:59 am
content: You would think no ballast LEDs themselfs would reach full on in less than a msec, but the power supply driving them may that at most 1 sec.How long have you had them and how many hours of use do estimate they have? If I have to change the tombstones then the ballast version are the way I would go too. I have read they are less efficient though.

author: edavid
author_rank: Super Contributor
timestamp: July 31, 2023, 01:28:37 pm
content: I installed them in 2017. I don't know the hours, but none of them are in high use areas. That said, they have already outlasted fluorescent tubes. I wasn't very worried about the ballast efficiency since I was already geting a nice savings by replacing 32W fluorescents with 18W LED tubes. For the ballasts I had to replace, I used Philips ICN4P32N35I, which has a rated ballast factor of 0.89, but I'm not sure how well that relates to LED driving efficiency. (BTW this ballast has a rated ignition time of 0.1 second.)

author: BlackICE
author_rank: Regular Contributor
timestamp: August 03, 2023, 08:44:57 am
content: I decided to stock up on fluorescent tubes 120 of them with 10 replacement ballast. I tested some Phillips LEDs (about $6 in quantity) rated at only about 1/2 the lumens and 1/2 the watts. I measured the light output using the spot meter of my SLR camera and it was only about 1/2 of bright as the fluorescent tubes, meets spec. I'm not willing to have dim lights are a higher cost to save power. There are some LEDs spec at more lumens using more watts at $16 / bulb! Given I don't trust the lifespan of LEDs using internal electronics, with ballast. I'm not shelling that kind of money on a hope. My fluorescent tubes are 16 years old and out of 126 bulbs I only had one fail. The light output has dropped by 20% in that time.

author: jonpaul
author_rank: Super Contributor
timestamp: August 04, 2023, 10:50:58 am
content: BlackIce: Just see now.I was EE/ekectronic ballast designer in 1970s..1990s, flour, CFL, HID, HMI, cinemawith Laurench Berkeley Lighting research, GE, Sylvania, 1984 LA Olympics1/ Magnetic ballasts are reliabile but poor efficiency, electronic more efficient but costly.2/ Use of the old FL tubes has been suplanted by LED replacement fixtures, and basllasts.3/ Ballast quality can be excellet (made in EU) or bad (China)4/ LED quality is similaryly quite variable5/ the so called LED fluroescent tube substutes are as noted low output.6/ In Paris and USA we removed all old FL tubes/ballast/fixturesWe replaced with Sylvania Helios gas cooled filament LED with 200 lumen/watt efficicy.https://www.sylvania-lighting.com/media/6737/sylvania-helios-led-brochure.pdfhttps://www.sylvania-lighting.com/en-int/news/items/helios-led-technology/Any colotr temp and infinite life!7/ Ballasts we used are the fine Italian TCI with slectable current and 0-10V or pushbutton on/off/dimming.https://www.tci.it/en/products/electronic-ballasts/8/ A colleague used CREE LED strips to make DIY fixtures with reflector and ballast.Hope this is useful!Bon chance !HAVE A ABSOLUTELY FANTASTIC DAY!Jon

author: GreyWoolfe
author_rank: Unknown
timestamp: August 14, 2023, 08:17:34 pm
content: When I replaced the 2, 4 bulb florescent shop fixtures above my workbench, I went with 6 bulb 48" LED shop fixtures from Home Depot. It was a perfect solution for me. I tried replacement LED tubes in the 2 bulb shop fixture in the garage but ended up replacing them with LED fixtures. The replacement bulbs were a bit better but proper LED linkable fixtures from Amazon has truly given me the light I needed in the garage-4 single tube fixtures lights up an oversized 2 car garage quite well.

author: BlackICE
author_rank: Regular Contributor
timestamp: August 14, 2023, 10:45:39 pm
content: That wasn't a viable option for me as I had 16 recessed 3 tube fixtures mounted at a angle from 12 to 14' above the floor. I real PITA to replace all the fixtures, not even factoring in the price. Another option would remove the ballasts and to rewire them with new tombstones for type C tubes. IMO type A and B tubes have more failure modes and are in the long run less reliable and more costly. Also a PITA. I'm happy with my choice of buying 120 Sylvania tubes that were originally installed before the sales ban in my state comes into effect. Interesting the originals made in 2005 are made in USA the replacement same part number made in China. I got over 16 years of use from the original tubes. Not bad. I doubt a combo of using old ballast with a type A LED tubes would fair as well.I have 126 of these bulbs in various fixtures in different places. Some of which I don't care if I need to replace the fixtures, others I don't care too much of the color temp changes or light output falls up to 25%. But one room I would like to keep bright with a good color temp. The 120 bulbs I brought should be a lifetime supply. I just replaced the 48 tubes and the room looks a lot better. I saved a few of the "better" used ones for backup use in less critical locations.

author: rhb
author_rank: Super Contributor
timestamp: August 14, 2023, 10:56:00 pm
content: I have a pair of $3 4' LED lamps in my EE space. I've also done considerable EMI testing. I have both a large EMI filter on the mains supply and 1/8" wire mesh over the whole thing. The EMI line filter has the most benefit. The screen is a minor improvement.The SMPS in my Instek MSO2204 is the major source of EMI at present.BTW I converted a pair of 4 tube commercial office fixtures today in about 30 minutes. Remove one of the socket strips, rewire for single end feed, no ballast lamps and replace.Reg

author: BlackICE
author_rank: Regular Contributor
timestamp: August 15, 2023, 12:03:53 am
content: Quote from: rhb on August 14, 2023, 10:56:00 pm16 fixtures * 15 mins = 4 hours labor. Mine would take much longer as the fixtures are high up and mounted at >30 degree angle. Just changing the tubes took well over an hour and that was with a helper so I didn't have to climb up and down the ladder many times for each fixture. I had to change a ballast on one fixture and used lever Wagos for the 1st time. Those are a time saver compared to twist nuts, but at a higher cost.Also note that most inexpensive 4' t8 LED tubes don't have the same 2900 lumens output, but much less. Yes you save power at the cost of dimmer lights. The lumens per watt are not that different. Finding comparable priced LEDs that put out 2900 lumens with 16 year lifespan IMO is impossible. Don't buy the BS that the greens are pushing how LEDs are superior. It depends on your requirements. If it cost effective long lasting lumens, current LEDs don't cut it. If its to have dimmer lights and saving power LEDs are the way to go, or just never use the lights and save even more.

author: edavid
author_rank: Super Contributor
timestamp: August 15, 2023, 12:34:13 am
content: I'm not convinced you did the light measurement correctly, since I have subjectively found "2000 lumen" LED tubes to be much brighter in real life than "3000 lumen" fluorescents. A spot meter is definitely not the right instrument.Also, fluorescent tubes that last 16 years? That's a joke, especially for recent production.You obviously have an anti-LED axe to grind, but I think it's great that I was able to replace dim, flickering, poor CRI fluorescent tubes with LEDs for $3.75 each. They even had a 5 year warranty (which I have not had to use).

author: themadhippy
author_rank: Super Contributor
timestamp: August 15, 2023, 01:14:16 am
content: If your florry fittings are the switch start variety no need to rewire ,just replace the starter with the one that comes in the box with the led tube and job done