Electure
The step down transformer I indicated is designed and UL listed just for this purpose. It might be a violation to us a Halo transformer on another brand of fixture but most recessed light manufactures have these transformers available. It is no different than the 120V or 277V transformers used to drop the voltage to 12V on low voltage recessed lights.
All of the CFL conversion kits that I have seen have an adapter that screws in to the existing medium based socket. I have never seen one that is designed for a 277V medium based socket.
Curt
