so out of curiosity, here is the scenario you have a auto shop with 4X F96T12 fixtures and you want to save power but you dont want to remove your awesome 4X F96T12 fixture
so you replace the magnetic ballasts for electronic ballasts would that save any power what so ever? and/or you change out your 75 watt bulbs for 60 watt bulbs would that make a big difference in power draw?
or would the ballast still run them at 75 watts ?

im just curios

Why so low power lamps in F96T12 ? Isnt there anything brighter you could put in along with ballast change ? (Are they single pin or HO ?)



With virtually all Magnetic ballasts, the change from Magnetic to Electronic alone saves a few Watts per lamp. An interesting part is, that not all the savings come from the ballast - The lamp itself gets higher Lm/W on high frequency supply, which means that Electronic ballasts actually put less power into it to ge the same light output as Magnetic

Here is some fairly precise data about European 36W 4ft T8, which have the same 3350Lm output on different types of gear. The magnetic ballast is a choke as used on 230V (so a suitable choke could be used in the US on 240V and 277V). Rapid Start and all other autotransformer magnetic ballasts are a bit less efficient, but while i know the figures for 36W T8 off memory, i dont know as much about Rapid Start and others

Standard magnetic

Power to luminaire 43W
Power to lamp 36W
Ballast losses 43 - 36 = 7W
Lamp efficacy 3350 / 36 = 93.1 Lm/W
Ballast efficiency 36 / 43 = 0.84
System efficacy 3350 / 43 = 77.9 Lm/W

Standard electronic

Power to ballast 38W
Power to lamp : 32W
Ballast losses : 38 - 32 = 6W
Lamp efficacy : 3350 / 32 = 104.7 Lm/W
Ballast efficiency 32 / 38 = 0.84
System efficacy 3350 / 38 = 88.2 Lm/W



It is technically possible to make chokes with high efficiency (size and cost are the limits), bringing overall efficiency to the same level as electronic. Here is what one of them might work like

Power to ballast 38W
Power to lamp : 36W
Ballast losses : 38 - 36 = 2W
Lamp efficacy : 3350Lm / 36W = 93.1 Lm/W
Ballast efficiency 36 / 38 = 0.95
System efficacy 3350 / 38 = 88.2 Lm/W

And it is possible to make better electronic ballasts too

Power to ballast 36W
Power to lamp : 32W
Ballast losses : 36 - 32 = 4W
Lamp efficacy : 3350 / 32 = 104.7 Lm/W
Ballast efficiency 32 / 36 = 0.89
System efficacy 3350 / 36 = 93.1 Lm/W

so out of curiosity, here is the scenario you have a auto shop with 4X F96T12 fixtures and you want to save power but you dont want to remove your awesome 4X F96T12 fixture
so you replace the magnetic ballasts for electronic ballasts would that save any power what so ever? and/or you change out your 75 watt bulbs for 60 watt bulbs would that make a big difference in power draw?
or would the ballast still run them at 75 watts ?

Electronic ballast would most likely run them at something less than 75w (other than the ballast-loss savings, that's the typical way they "save" energy with ballasts)
Don't bother with 60w lamps, they still suck in cold (or even cool) weather. No flickering on electronic, but they will be dim.

You could upgrade to F96T8 as well.

-----------

Why so low power lamps in F96T12 ? Isnt there anything brighter you could put in along with ballast change ? (Are they single pin or HO ?)

F96T12 75w would always be single pin.

If the 60 watt tubes dim when cool / cold you can get glass tube guards to reduce this from happening, and normally I would suggest plastic tube guards but in a paint shop, you'll never get the paint off them and will need to replace them all the time but a glass guard you can wipe down with paint stripper and reuse them..

Also on a side note, will the ballast change alter the fixtures class and division ratings, or totally invalidate them ? most of the paint shops I've been in use Explosion proof fixtures, most paints are highly explosive when you spray them, so you have to change the ballast and lamps as specified by the manufacturer, simply putting in lower wattage parts may not be allowed by code (your insurance company will have a issue with this, and if there is a fire / explosion they will find out what caused it) you might really be looking at power savings vs the potential for a fire/explosion and no insurance coverage, so it might be cheaper in the long run to go with a whole new fixture that has the proper rating and lower wattage your looking for, or pay a little bit more for power...

How large is the painting area (specifically the explosion risk area) ? And how often the light there is in use ? (can it be wired to a separate switch when not in use ?) For a small workshop it may be using too little energy to bother in the first place

I have experience installing F40T12 electronic ballasts alongside F40T12 magnetic RS ballasts in the same fixtures. Both ran the lamps equally bright, and the electronic ballasts were rated 0.63 A with 40w lamps compared to 0.73 A for the magnetic ballasts. So the efficacy is indeed higher with electronic ballasts (which is the point).

Magnetic normally have power factor around 0.9 (for HPF ones), good electronic often higher

Magnetic normally have power factor around 0.9 (for HPF ones), good electronic often higher

But the NPF magnetic use to be around 0.6, the electronic with very simple power factor correction (just a series inductor with the input,...) use to be around 0.7 or so.
But indeed, there is difference in losses (10..15W for magnetic is quite good result; 5W for electronic is quite typical), but don't forget the HF ballast needs to feed the lamp by about 5..10% lower power for the same light output...

I would say it's debateable. 

The electronic ballasts are indeed less lossy.  From what I've seen, the F96T12 electronic ballasts run the 60w energy savers without striating in cold, which is nice, though if it's really cold they might not be terribly bright.  Not sure if they'd run 75w any dimmer but being we're stuck with deluxe halophosphate lamps now in the US and Canada for full wattage (75w), which have high CRI but are not very bright, so of course if you could find, say, some old stock F96T12/SP65 you'd be much better off in terms of brightness.

The best 60w lamp I can currently recommend is the GE HL-xx series.  3500K, 4100K, 5000K and 6500K versions exist.  The F96T12/ HL41 is a 4100K, 80 CRI deluxe triphosphor (I THINK) lamp which for being an energy saver is decently bright but has a bit of a peachy color so if you're spot relamping 60w cool white and/or 75w cool white deluxe they might not quite match if you're picky about color temperatures matching.  (I personally couldn't care less about mixed color temps but that's just me, but it's not for lack of knowing any better, I know what the lamps are).  The HL series also exists in High Output.  These seem to be available in hardware stores and I'm not sure on lumens but I'd say they're better in terms of brightness than 75w cool white deluxe or 75w Chroma 50 or 75w Daylight Deluxe, believe it or not, but in a cold garage you'd be best to stick with 75w since they're way less cold natured, the 60w lamps absolutely suck on magnetic ballasts in even cool temperatures, such as being near an A/C vent, forget an unheated garage.  In subfreezinng but above zero temperatures, they will light, but will be dim and flickery enough to be annoying and warrant their replacement for 75w deluxe halophosphate. 

Or, I hate to say it, but consider retofitting the fixture to electronic F96T8.  Electronic ballasts, which behave better in cold, and 59w full wattage lamps, (not sure what the energy saver version is but I'm sure one exists, I just haven't seen them).  Still a neat/vintage/retro 4 lamp strip light or industrial but saving a few watts and less cold natured.  While I like my magnetic F40T12 rapid start fixtures, as ballasts quit, since I have many T8 fixtures in use too, I'll probably just retrofit them to F32T8.