Qavion
Absolutely correct!
Anyway, we did the experiment and it all worked as advertised. Gave them a total 'gennie' failure to set the condition and left it for a while to check the annunciations. As expected, (IRS3) on the ND and it stayed that way. We couldn't afford the time to wait the full 5 minutes for the Centre IRU to switch off automatically, so I manually switched it off after a minute or so. Again, as expected, (IRS L) was the annunciation.
One interesting bit of info, which I hadn't looked at before, was the indicated discharge rate for the Main and APU batteries - 64 and 61 respectively - and that was without doing any electrical system 'housekeeping'; so the 30 minute power availability is obviously no problem at all.
I'm about to post a query re 400 hydraulics - would be interested in your thoughts.
