I finally made an account here the other day and have a question regarding T8s and electronic ballasts that has been on my mind for some time now. What kind of ballasts were common in older T8 installations, in the U.S. in particular? I am aware that there are magnetic T8 ballasts although these seem extremely rare since most T8s are run on electronic ballasts. Some time ago I read that electronic ballasts were invented in the early 1990s (maybe even before then) but prior to about fifteen years ago, they used a magnetic coil to drive the tubes and the only electronics were contained in the starting circuit of the ballast. I was born in 2000 so I grew up during the T8 pandemic and am now witnessing an even worse LED pandemic. By the time I had gotten into lighting they had stopped producing magnetic ballasts altogether.

So back to what I was originally saying...the reason I ask is because I have seen a lot of fluorescent installations from the late 90s/early 2000s where T8s had been used. Now as to whether or not they are original, I cannot say for certain. But I do know that the Walmart near my parents house (which was built c. 2005) originally had rows of 8 foot fixtures, 2x 4' T8s in tandem sections with a 4-lamp ballast per fixture (the store became LED'ed about three years ago), and yes they were those rapid-start dimming ballasts that used to be common in just about every Walmart that had skylights; they were controlled by photocells in the skylights, and would dim when the sun was shining to save on energy costs. Prior to 2014 or 2015 when the entire store was re-lamped and many ballasts were replaced, in the fixtures that had been failing I couldn't tell which ones had bad tubes and which ones had faulty ballasts, as they were connected in series so if one lamp/tube went bad then the other three tubes in that fixture would also appear to have failed. Some would have all four tubes flickering dimly and others would have all tubes completely out. In a couple instances, I recall seeing all four tubes glowing bright orange! I saw something similar at a grocery store I used to work at that had 8' T8 slimlines, except when one tube would go mercury starved the other one wouldn't light at all. That store was built in the 80s or 90s though I believe those fixtures originally had 8' high-output T12s in them and were retrofitted sometime in the 2000s. My grade school, which was built only a couple years after I was born, had also been lit entirely by T8s. I never recall seeing a burned out tube or ballast except on a couple instances, I'm pretty sure the maintenance crews there ended up installing Advance multi-volt ballasts and new tubes district-wide like they did with the 50s louvered fixtures at the middle/high school later on. And yes, I've heard buzzing coming from a T8 fixture, a 4-lamp troffer in a convenience store near my folks house that had all four lamps working. It wasn't like your typical magnetic ballast hum, I'd say it was a slightly higher pitch and actually louder! Not sure the age of that fixture and as far as I know it's probably been LED'ed by now (I could be wrong). It's about an hour drive from my current place so I'll have to check it out next time I go back home.

I'm just interested to know about these early electronic ballasts, if they are even "electronic" like everyone says. I know T8s get a lot of hate on this forum lol but at least they're not LEDs!  If anyone has a picture of these ballasts, please send them...the oldest electronic ballast I've seen was from approx. 2006, an Advance multi-volt instant-start ballast for 3-4 T8 lamps, before they were bought out by Philips (?) and switched to the blue label (it had a rainbow-ish label as I recall, aside from that it is virtually identical to the ones still being made). It is in a troffer my dad installed in the basement and is still in use to this day, though it doesn't get much use as it is in a storage room.

First of all, welcome aboard! 

It just so happens that I recently found four Advance electronic ballasts that I had laying around, and that somehow were not disposed of when I had to downsize my collection a few years ago. They seem pretty early, maybe pre-2000! Their casing is strangely old-fashioned, without those two tapered edges typical of RS ballasts from the 60s and later. And I think they're 4-lamp ballasts!

I don't remember ever testing them. Maybe once but I can't be sure. I used to have F32T8s, not anymore LOL.

I have a few older electronic ballasts, the oldest being this Advance from 1999. Oddly I believe it uses a fully electronic design. It does have what I call a full sized case, it's actually the exact same size as a standard magnetic ballast. I believe it was made shortly after Advance dropped the Mark V branding for fully electronic ballasts.

My second oldest is this Sylvania ballast. It's actually a relabeled Motorola ballast, Motorola used to make ballasts until the 2000s when they sold off their ballast division to Sylvania. Like the Advance from above, it's also a fully electronic design. Interestingly, it's rpaid start electronic ballast which is quite rare to see. The removable leads was also a thing that Motorola liked to do with their ballasts.

It's not a T8 ballast but I also have this Advance F96T12 from the early 2000s. This one is quite interesting, it's a electronic ballast with high frequency operation but some of the elements inside are magnetic and it even has the hum to boot. I have a T8 one from the same era that's probably built the same internally. It also has the same characteristics.

Finally, during the early days of T8, it was common to use magnetic rapid start ballasts for them. Here's a example I have from 1986, fairly early for T8 which were only introduced 4 years prior. Magnetic T8 ballasts continued in production until sometime in the 2010s but most places started using electronic by the late 90s. The late 90s seemed to be when you could see both types being installed. My high school had an addition built in 1999 and it was originally equipped with all magnetic T8 ballasts.   

There was also the Advance Mark IV PowrKut ballasts, those were actually just standard magnetic ballasts that had a extra electronic circuit in them to reduce the cathode heating supply after startup to save a few watts. The ballast was still for the most part a magnetic ballast with regular line frequency operation.

If you're hunting for a older electronic ballast, you could try searching the part numbers in the pictures or just keep your eyes out for any electronic ballast that's a major brand and is: 120v only and has a full sized case. I think after 2005 or so, multi volt electronic ballasts pretty much got rid of the 120v only models.

@ Joseph:
Using the same size of casing for those early electronic ballasts just after they had stopped making the magnetic lumps does make sense. 

They would want to use up any of the old cases left over.

My hunch was that the early electronic ballasts required the full size case due to the components used or the PCB size. The reason being that they switched to the smaller case in the 2000s to cut costs when the magnetic ballasts were still being made. In the late 2000s they reduced the case size again to the slim case that modern T8 ballasts use. The mounting has been kept mostly the same though if you use the two main slotted holes on the case.

The university here converted all fluorescent (save for a few miss outs) to electronic T8 in 1997, if I remember correctly. They were MagneTek, with a full size case. I have one here, I must check the date stamp. They were almost as heavy as their magnetic counterparts, but not quite.

The one I attended converted in 1995 using Osram T8 ballasts. I had a chance to obtain one but they were 347v only so I passed. Anyway they had full sized cases.

I should really dig out the Advance I mentioned in my other post and compare it to a magnetic ballast.

@joseph_125, those are some neat finds, especially that Motorola ballast...I've seen many newer electronic ballasts from the last decade but have never seen them without leads. Surprised those push-in connectors never became more popular as it would make replacing the ballast a hell of a lot easier! Also have yet to see a 347 volt ballast, or 347 volt anything really, as here in the US 277/480 volt 3-phase is typically used in large commercial and industrial settings. I feel like 277 volts is about as common in Canada as 347 volts is here, though maybe I'm wrong lol... 

Yeah the Motorola/Sylvania ballasts are pretty unique in that regard. There are some electronic ballasts from Universal and Advance for CFLs that are like that too but a fluorescent ballast with those push in connectors are rare.

On the flip side ballasts with detachable leads are pretty common in European countries and other 240v countries.

I believe 277v is common in Western Canada in provinces like Alberta, in Ontario 347v is the norm. 347v seems to be a bit inconvenient as 277v can use the same devices (most commercial switches are rated 120-277v) and ballasts with the multi voltage ones while 347v requires 347v specific switches and ballasts. Even the boxes and cover plates have to be 347v specific versions. You can tell in most commercial places what lights are on 347v from the stamp on the switch cover plate.

Interesting. As I said I'm not at all familiar with 347 volts, didn't realize that even the hardware had to be designed specifically for this voltage.  I know that most Romex wire is rated at 600 volts which is the phase-to-phase voltage of 347. We also use 600 volt isolators on 480 volt circuits here in the US. I guess the only advantage of using 347/600 volts is because of the higher voltage, less amps is required so smaller conductors can be used.

As far as 277 volt switches, I prefer these over the 120 volt contractor grade switches that cost a buck at the local hardware store, they seem to last longer and most have a higher current rating (20 or even 30 amps opposed to 15 amps) which I suppose is more sufficient for inductive loads, like motors and magnetic ballasts. I have seen these types of switches in use for 50-60 years and still going strong. Before I moved out of my parents house, my dad and I had to replace numerous of those contractor grade switches, some had started feeling loose and others would make an audible ZAP! when flipped. Not to mention that most of these switches were less than a decade old.

Yeah, I believe 347v wiring devices even use a different hole spacing to prevent them from being used in the wrong junction boxes. The boxes are similar to the ones used with 120/277v but the single gang boxes are wider than standard boxes and the multi gang boxes are required to have dividers between each device. Interestingly 347v receptacles are also made too although aside from high bay lighting, I'm not sure what would use them.

I also prefer the 277v rated "spec grade" switches compared to the standard residential grade ones. They seem better built and I think have a stronger spring which makes the switch snap open/closed quicker compared to residential grade. I also prefer the "spec grade" receptacles over the residential grade ones too. They have dual wiper contacts which seem to last longer and grip plugs better compared to standard outlet.

I recently got hold of a pretty early electronic T8 ballast that had a date code of March 1993. That's pretty early for electronic IMO. It's this Osram Quicktronic QT-2x32/120 IS. It wires up similarly to a modern electronic instant start T8 ballast but has it's own ground wire instead of being grounded through the fixture. The case is also the same size as a magnetic ballast too. It's also 120v only like most older electronic ballasts.

In the history of Toshiba in Japan, I learned that Toshiba incorporated electronic ballasts into their spherical CFL "NeoBall" as early as the 90s, releasing "Electronic NeoBall". Philips also launched electronic ballast CFLs in the 90s, such as "SL Electronic" and "PL Electronic"