Hey everyone! Wondering if they ever made any incandescent bulbs that where either 208,277,347,415,480 volts to be used with a 3 phase supply. I know step down transformers exist , but i want to know if they made any bulb where that wasn't possible to use. thanks for any cool facts/ info. 

277v incandescent lamps were made in various wattages in both medium and mogul base. I believe the lower wattage medium based lamps were intended only for temporary lighting as the NEC prohibits connecting medium based lampholders directly to a 277v circuit. The higher wattage mogul based lamps might have saw some use in incandescent high bays back in the day.

The street railway incandescent lamps were also interesting, they were rated at 120v but were designed for use in streetcars and subway trains that used 120v lamps in 5 lamp series strings on the 600v traction power supply.

I know 277v bulbs exist as I have a few of them.

277v incandescent lamps were made in various wattages in both medium and mogul base. I believe the lower wattage medium based lamps were intended only for temporary lighting as the NEC prohibits connecting medium based lampholders directly to a 277v circuit. The higher wattage mogul based lamps might have saw some use in incandescent high bays back in the day.

The street railway incandescent lamps were also interesting, they were rated at 120v but were designed for use in streetcars and subway trains that used 120v lamps in 5 lamp series strings on the 600v traction power supply.

I know 277v bulbs exist as I have a few of them.

ok thanks for the info! btw do you have a post of them in your gallery you could link for me? thanks! 

ok thanks for the info! btw do you have a post of them in your gallery you could link for me? thanks! 

  It can be seen  here

I think I read somewhere that the NEC prohibits medium sockets from being connected to anything higher than 120v in a residential setting. 240v bulbs are only supposed to be used in commercial environments to my knowledge. Interestingly, 300w medium based bulbs were also against code in the late 1930s or 1940s, but they still sold them.

I’ve never seen a bulb that runs at higher than 277v (aside from one bulb meant for 277v but designed and labeled for 300v to increase life) designed for a medium socket. I would expect there to be serious issues with arcing in the socket at higher voltages if the socket became dirty.

277v seems to be a more recent industrial voltage for lighting, as they don’t mention it in lamp catalogs of the ‘40’s and ‘50’s to my knowledge. They did make a large lineup of 240v bulbs for industrial settings in environments where no lower voltages where available (EX. a building with 220v delta service). I’m not sure if large 208v bulbs existed, but they used to offer 110, 120, 130, 220, 230, and 240 bulbs back when line voltage varied significantly from place to place. 208v bulbs don’t make sense since you could take 120v from one of the 3 phase legs to ground. Oddly, they did make 196-212 volt (nominal 208v) fluorescent ballasts in the 1940’s.

The higher voltage is not that much problem for the socket, but mainly for the structure inside of the bulb.
It needs larger distances, or modify the fill to make the internal arcing less frequent so it would become somewhat usable.
The larger distances mean the lamp must be physically larger, hence the mogul/E40 sockets.
The modified fill means the lamps become less efficient, with voltages going above 300V to the extent of becoming nearly unusable.

The most common solution is to just split the voltage by series connection of multiple lower voltage lamps (like in the street xars,...), sending the higher voltage rated lamps to obscurity (even when lower wattage, the lower voltage allows the series connected system to be way more efficient and the use of common bulb types way cheaper)...
Some special cases needing just one lamp (e.g. for signal purpose - like streetcar switch state,...) usually use either series ballast resistor or a transformer (if it uses AC power), again to end up with a common lamp type.

Higher voltage lamps do exist in linear quartz infrared types.  These are often made for direct cross-phase connection on 380/400/415V mains.

  Google “ GTE Sylvania Accused of Bribing Subway Engineer” brings up an interesting New York Times article from 1977
concerning the 36 watt street railway lamps. NewYork City Transit Authority specifications called for the 36watt street railway
lamps to be the A21 bulb size. Sylvania paid bribes to a transit engineer to change the specifications to the A19 bulb size.

The weirdest light bulb voltage I’ve seen was 121v and 17v

I have read that some GE linear halogen floodlight fixtures would take 208V linear halogen lamps.

 There's a pair of 208v Self-Ballasted Mercury lamps on eBay right now .

 Look thru this GE catalog on LampTech. https://www.scribd.com/document/113710933/GE-1975-Lamp-Catalog  There's lamps from 6w to 1,500w using all sorts of 120+ voltages from 135v to 300v using bases from Candelabra to Mogul !

 My favorite is the 10w , 250v D.C Bayonet indicator lamp ! 

 There is a 25w & 50w medium based A-19 listed as 300v. The 1st 277v listing is for a 100w A-21

I might get a couple for myself to run off my step up transformer.

Can you send me the link to those 208V self ballasted mercury vapor lamps you found in a PM?

  I'll see if I can find them again . They were listed in web finds at one point . IIRC they were a good bit over priced .

 EDIT : I can't seem to find them . I'm assuming the listing expired . If I see them again I'll let you know .

277 volt incandescent  is a  single phase  of 480 volt 3 phase supply.   It leagal to use  in the  industrail enviroment.   

  But in resdentail wiring  only 120 volt must  be use  for medium basw socket.   That becase  240 volt  is uses  two  hot wires   This leaving screw shell energize.   
  This also phase to phase  to lamp socket for this reason.

    How ever there is a rare  208  self  ballast MV floating out in the  wild.