B777 Back-up electrical system - TCAS
As I understand it if the power to one or both of the main AC busses is lost the backup electrical system automatically powers one or both transfer busses as required. To reduce electrical loading on the backup generator, the TCAS is not powered and is therefore inoperative.
Does shedding power to the TCAS have any impact on other Mode S transponder functions? (eg is ATC SSR impacted?)