fingal flyer

Just wondering why they both go off when apu is running electrics and thrust levers are advanced.IE engines shutdown.Suspect it is load shedding due to a/c logic suspecting double engine failure but can anyboby help an ignorant pilot.

Short_Circuit

Yes f.f., it is load shedding due “single power source” supplying buses with thrust levers advanced.
S_cct

NSEU

It's probably like the 767 which loadsheds in the air with a single power source. On the 767, Boeing defined "in air" (wrt to loadshedding) as weight off wheels(bogey tilt) or thrust levers advanced (presumably as a backup for the gear tilt).

Rgds.
NSEU

flyboyike

The CRJ does the exact same thing. It doesn't even have to be in the air. All it takes it to be single-gen, main door closed, flaps out of zero.