Ah, thanks for the correction. I believe the Motor-Alternator set is unchanged from the 319 and so will have been designed, like the traction electronics, to operate properly over the input voltage range experienced on third rail.The compressor is powered from the MA set and is not tied into the Bus lines only the traction /Flex ties directly to the Bus
The fans are inverter driven from the flex side on the engine rafts and have no mechanical coupling
Am I correct in thinking that the engines need to run at a speed above idle to power all the auxiliaries that are supplied via the MA (compressor, lights etc.)?
Edit: I have since been informed by someone familiar with the units that the main (brake) compressor on the 319 and 769 is powered directly from the 750V DC bus. There is an auxiliary compressor powered from the batteries (which are charged by the MA set), but that only supplies air for raising the pantograph (not on the TfW units obviously).