Same fundamental problem, slightly different technical difference. It's my belief that its not common knowledge that electrical apparatus that exists between the line and actual LEDs perform the same duty and works essentially the same as fluorescent ballast.
Same fundamental issue. Different specific lamp type.
LED + external power unit vs LED with built in ballast
PL-C 4-pin 13W + external power unit vs corkscrew 13W with built in ballast
There is also the practical concern about the dangerous conditions created by ballast bypass lamps. You can't reasonably expect people to not insert T8 lamps in a T8 socket anymore than a warning sticker on a normal outlet warning people about only plugging in a very specific item. The consequences can expose real people to injury. I think concern for liability is the reason why GE/Philips/OSI are not offering the dangerous "type B" product here. Some guy on garage journal experimentally blew up a lamp with a retrofitted socket. Check out his posts here:
http://www.garagejournal.com/forum/showthread.php?p=4825366
Almost always when I am asked to do one of these jobs, the existing ballast/tubes are T12.
Magnetic ballasts are hardier than electronic and they tend to fail less suddenly. There are some LED lamps for T12 magnetic ballast. Philips has one that is rated 2100 lm 4100K 83CRI.
T12 lamps are not illegal contrary to common beliefs. The ones that are readily available now have excellent CRI to comply with the new law. CRI is 89, 2550 lm. They claim to save about half wattage, but at 2,100 lm the output doesn't match and how much dimmer just depends on what type of T12 lamps they have and what they have available in their stockpile. Pre-ban 40W lamps were anywhere 3100 to 3600 lumens for 40W.
The LED tubes that run off a T8 ballast are much less expensive (about $7 each for 4ft) than either the direct wire tubes or the ones that use a T12 ballast. I find the most cost effective way to do this job is to replace the ballast with a new T8 and then use the T8 LED tubes.
The cost of absence of ballast adds up as the ballast is external. I think production volume has a lot to do with the cost. There's definitely more glass and rare earth in 32w T8 than 2' 17W but you know which costs more. Philips has proprietary LED power pack as well as ordinary T8 ballast such as the NEMA Premium ICN-2P32-N and both of these will perform more efficiently than a T8 ballast from 1990s. I do not know if the proprietary pack offers meaningful benefit, if at all over the common ballast.
My clients seem to be more concerned with electricity savings and less concerned with long term maintenance (i.e. changing the ballasts). I have no idea how long ballasts last when driving LED tubes. I suspect they last as long or longer. If research shows they don't last very long, I would change my recommendation to clients. Also if they were high-mounted lights, direct wire would make more sense since using a lift to maintain adds costs.
Direct wire does not make sense. They're a safety hazard, and wiring method is inconsistent so there's a good chance it might have to be rewired to match the available replacement self ballasted lamp.
) and less concerned with long term maintenance (i.e. changing the ballasts). I have no idea how long ballasts last when driving LED tubes. I suspect they last as long or longer. If research shows they don't last very long, I would change my recommendation to clients. Also if they were high-mounted lights, direct wire would make more sense since using a lift to maintain adds costs.
