# LED Ballast Bypass Lamps for Fluorescent Troffers



## Les (Aug 19, 2018)

We have about 24 of the 4-lamp suspended-ceiling T12 troffers spread throughout our greenroom, dressing rooms, and backstage hallway areas (including stairwells). Last year I went through and did a total relamp since about 75% of the lamps in each room were in some stage of being burned out. That fixed about 95% of the issues, but one year later they are back at it again. The weird thing is that the lights act like it's all or nothing. You can walk in a room and flip the switch and they all turn on dim (or maybe one fixture out of four will turn on at all). Flip the switch on/off a few times and usually they will all turn on, at least for the most part.

I'm not really thinking it's a wiring issue. The wiring is all 25-year-old THHN run through conduit. I think we have a bunch of bad ballasts. So my thought now is to go through each room systematically and replace all the lamps with LED ballast-bypass versions like these.

I know there are some needs as far as the sockets are concerned - that they can't be the "shunted" version; but I have a multimeter and can confirm that as needed. 

Has anyone had any success with these (or similar)? I know there are two flavors of LED retrofit lamps available -- plug-n-play and ballast bypass. I lean towards ballast bypass since failing ballasts is the reason I'm wanting to retrofit these lights in the first place. The lamps I linked to are about $6.99 each which seems like a good price, but I am also open for suggestions. I want to save money but also live by the adage "buy once, cry once".

I'd really rather not drop in entire fixtures if I can help it, due to labor and cost ($28 per fixture to retrofit) but maybe I could be convinced of that as well.


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## RonHebbard (Aug 19, 2018)

Les said:


> We have about 24 of the 4-lamp suspended-ceiling T12 troffers spread throughout our greenroom, dressing rooms, and backstage hallway areas (including stairwells). Last year I went through and did a total relamp since about 75% of the lamps in each room were in some stage of being burned out. That fixed about 95% of the issues, but one year later they are back at it again. The weird thing is that the lights act like it's all or nothing. You can walk in a room and flip the switch and they all turn on dim (or maybe one fixture out of four will turn on at all). Flip the switch on/off a few times and usually they will all turn on, at least for the most part.
> 
> I'm not really thinking it's a wiring issue. The wiring is all 25-year-old THHN run through conduit. I think we have a bunch of bad ballasts. So my thought now is to go through each room systematically and replace all the lamps with LED ballast-bypass versions like these.
> 
> ...


 *@Les* A couple of quick observations before I delve into sourcing an affordable synchronized clock for one of your other posts. 
*Observation #1;* Often times when I've seen this behavior with fixtures containing four or eight CW T12 four footers, I've reduced the problem by pulling in dedicated green jacketed ground conductors rather than depending upon set-screw and 'rain-tight (Thomas & Betts) 1/2" or 3/4" EMT connectors to ground the fixtures via lock-nuts installed by hand by installers in a hurry not making the effort to dig the conduit connector lock-nuts tightly through the two layers of white powder-coat where the EMT enters the fixture. 
*Observation #2;* One entire venue used to be lit by endless rows of dual CW 4' T-12's. One summer the city sent in a contractor to swap every pair of dual CW 4' T-12's with end to end 8' fixtures with each 8' fixture containing one ballast powering 4 x 4' CW T-8's. Result: Essentially the same light WHEN THEY WERE WORKING but we seemed to be replacing FAR MORE tubes and FAR oftener. If we fell behind in re-lamping we quickly learned we ended up having to replace FAR more ballasts as well. Purely as an untested observation, it felt as if we were running the T8's with 'the pedal to the metal' to get as much illumination from their smaller amount of internal light emitting phosphor. Don't know, can't say. All I can say for certain is my mates and I sure had to replace far more tubes, far oftener and if none of us happened by for a month, we ended up having to replace more ballasts as well. 
*As a bonus aside:* The last PAC I was working on when my head erupted had a combination of trendy new 4' T5 fluorescents with a sprinkling of similarly sized 4'-ish LED's. These were in corridors throughout all floors of the twin-venue complex with the LED fixtures periodically inserted in 24 / 7 / 365 night light / Emergency locations. The electrical contractor was having difficulty keeping them all operational long enough to install stainless plates and vacate the building. The contractor had blown through all of the nominal 10% spares he was contractually obligated to leave behind and had to order more tubes to leave behind for stock. 
Toodleoo! 
Ron Hebbard


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## Les (Aug 19, 2018)

Ah, I hadn't even considered a grounding issue. Ballasts are picky about that. I don't think I have the means of pulling new wire, but I could at least remove the powdercoat when re-landing the ground if I go through with an LED retrofit. The bypass lamps don't give a ____ about whether they're grounded or not, but I'll certainly want to make sure the fixture housings are properly earthed.


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## Ben Stiegler (Aug 19, 2018)

I converted my own shop using the same type of lamps you linked to, also changing out the ballasts. All were fed from a single switched circuit on which I'd previously installed a Leviton motion sensor switch. I had all sorts of weird behavior with the LED tubes flickering on and off dimly ... but not all the tubes. I was pretty sure I hadn't miswired anything - and I was right. What I found was that the 15 year old Leviton motion sensor switch wasn't compatible with LEDs (eg, it didn't connect to the green wire, too). Replacing it with a new Leviton motion sensor switch solved the problem (after only a year of puzzling) and now its either dark or fully light in there, hands free.


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## BillConnerFASTC (Aug 19, 2018)

i strongly prefer 3k over 4k but go for it.


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## RonHebbard (Aug 19, 2018)

Les said:


> Ah, I hadn't even considered a grounding issue. Ballasts are picky about that. I don't think I have the means of pulling new wire, but I could at least remove the powdercoat when re-landing the ground if I go through with an LED retrofit. The bypass lamps don't give a ____ about whether they're grounded or not, but I'll certainly want to make sure the fixture housings are properly earthed.


*@Les* As you mentioned, grounding each fixture's metal enclosure (and thus its ballast) is important. Fluorescent tubes seem to fire and sustain their output better with a nearby ground plane. I get the impression the grounded metal housing behaves somewhat akin to a reflecting element on a dipole antenna but I *won't put that thought in print*. 
Toodleoo! 
Ron Hebbard


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## RonHebbard (Aug 19, 2018)

BillConnerFASTC said:


> i strongly prefer 3k over 4k but go for it.


 @BillConnerFASTC @Les and @Ben Stiegler et all. Personally I'm preferring 2900 and 2950 if we're veering off into color temperatures for general work / task illumination. 
Toodleoo! 
Ron Hebbard


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## BillConnerFASTC (Aug 19, 2018)

RonHebbard said:


> @BillConnerFASTC @Les and @Ben Stiegler et all. Personally I'm preferring 2900 and 2950 if we're veering off into color temperatures for general work / task illumination.
> Toodleoo!
> Ron Hebbard


Hard or impossible to find in common LED fixtures and lamps.


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## JD (Aug 19, 2018)

Do not go with "plug-n-play." The ballasts can fail open requiring you to go back and re-fix them. Also, the ballasts will still be wasting current. Rip them out, change to bypass. Once you get ti down to a system, the changeover is about 10 minutes per fixture. 
As for color temp, go with the ~3k as it is easier on the eyes. Fixtures put out just as much light, although the lower color temp may give the impression they are dimmer in rooms that also have windows due to the color miss-match.


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## tjrobb (Aug 20, 2018)

Sans LED, this is either a ground or ballast issue. Fluorescent lamps like good grounding or no ground, meh grounding makes them temperamental. Also, since "flashing" the switch tends to help, that might be a weak ballast; in effect the ballast can't heat / pulse the electrodes hard enough to generate a self-sustaining arc inside the tube. (Aside, it's a fun time to install a new tube on a weak ballast and watch as it pulses along faster and faster until it finally "catches" and stops strobing).


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## Dan Thoms (Aug 20, 2018)

Hello, about a year and a half ago, I replaced the Office troffers with the ballast bypass LEDs. (about 150 bulbs) They have been great! Not a single bulb has gone bad yet! I was going through a box of 30 T8 bulbs every other month. This past spring I replaced the warehouse bulbs, they are on motion switches, these have also been working great. Color temp is a very personal decision. I prefer 5K, but I've put some lower value bulbs in select offices, in general everyone gets use to the 5K.


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## BillConnerFASTC (Aug 20, 2018)

It would be an interesting research if you put 3k in a few spaces and asked people to compare and indicate preferences.


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## Les (Aug 20, 2018)

BillConnerFASTC said:


> It would be an interesting research if you put 3k in a few spaces and asked people to compare and indicate preferences.



I may in fact do that. We have makeup lights so the fluoro's are usually used for utility purposes in those rooms. However, it's not uncommon for costumers to use the dressing rooms during off-hours to do their thing, so I could see 3K being beneficial across the board. This is something @teqniqal has pointed out to me as well. Now is a better time than any.

Thanks everyone for sharing your experiences! I did some math and it should cost somewhere between $500 and $750 to retrofit these spaces. Shouldn't be too hard to fund.

I already have a small amount of 4K tubes awaiting installation, but they'll most likely go in the public restrooms. With the already pinkish hue of the wall tile, 4K lamps should balance out as far as the room look goes.


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## danhr (Sep 3, 2018)

I upgraded my garage, basement and the 120v fluorescent fixtures in our theater space (the majority are 277V) 2 years ago with line voltage LED lamps and have had no issues. The garage is unheated (check local listings) and they don't care what the temperature is. Since the ballast is usually the problem I see no logical reason to use the "plug and play" type lamps. You're also saving more energy removing the ballasts (tho I'm not sure how much).


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## Chase P. (Oct 30, 2018)

Les said:


> I don't think I have the means of pulling new wire,



Might be a great opportunity to upgrade a bit and add separately controlled running blues in the stage-adjacent areas. If the ground is indeed the problem, calling it a health and safety issue (over just a re-lamping inconvenience issue) might get you the funds. Add in the potential insurance issue every time someone has to climb a ladder and toy with a poorly grounded device, and re-wiring starts looking good!


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## mikefellh (Nov 9, 2018)

If you want a test to see if your fluorescent light has an old magnetic ballast vs. a newer electronic ballast, use your cellphone (or any camera that has live view):

If you get a rippling image, it's a magnetic ballast:



If you get no rippling, then it's an electronic ballast:


I accidentally discovered this effect when photographing glass slides on a fluorescent based light box.


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