I recently saw a 1500 watt linear T3 halogen bulb on eBay that is rated at 277 volts.  If I were to run it via my voltage transformer at 230 volts, would it be slightly less than full brightness with a longer life expectancy?  I am considering finding a large linear halogen fixture to run one of these spectacular halogen lamps someday.

These halogens were popular on stage installations, the voltage suggest US or CA territory.

These lamps use to have one problem for a general user: They do emit way too much UV to be deemed UV safe for people, so they need a filter glass in front of the lamp.
Some fixtures were lacking the UV filter, as those were intended for just a brief ON time (an effect lighting), some have the filter glass missing, the new, complete ones would be an Unobtanium these days...

I think Canadians use 347 volts rather than 277..

That’s very interesting, thank you for your help!  I seem to remember seeing a 400 and something volt T3 halogen that is 1500 watts and labeled as a heat lamp for food. That makes sense that a higher voltage halogen lamp emits more UV radiation and is more intended for short term lighting or as a heat source.

A heat source lamp would be somewhat lower temperature so less UV..

It might, but also consider that the halogen cycle doesn't always work as intended on cooler filaments. Seen dimmed bulbs blacken. But hey, if you want to go for it!   Just make sure its UV shielded as others have mentioned.


277 volts is present in commercial buildings- its preferable to use that (less wire, less step down transformer kva, less V drop) especially when feeding heavy loads. 

Figure this lamp was made for 277V lighting systems in buildings that have 480/277V 3 ph service.You get 277V if you go phase to neutral in 480V systems.If you can get 1500W 277V somehow-like from a step up transformer you could use the lamp in a fixture with a borosilicate glass lens that can withstand the temp of the operating bulb-and would have to be strong enough to contain fragments in case the lamp ruptures.