Dead battery -> unable to connect APU/GPU?

[vesalius]

Hello,

Situation:
Cold and Dark state.
Turn on battery switch
Turn on APU but do not connect the GEN's
...
As expected, battery was drained after some time.
But at this time I could also hear the APU powering down.
On the overhead, APU EGT remained at approx 300C but the APU GEN OFF BUS indicator extinguished.
I could not connect APU GEN's

I connected GPU, overhead indicator GRD POWER AVAILABLE came up but I cound not connect GPU BUS
When I disconnected the GPU, the indicator extinguished.

All the best,
Vital Vanbeginne

[Litjan]

When the battery drains to 0, the temperature indication of the APU becomes dead (stops at last value). The APU will shut down as well (like when you switch of the battery).

The generator breakers need electricity to work - so with a totally depleted battery, you can not close the APU, GPU or engine generator breakers to connect them.

In this case in real life the following things happen:

1.) The Captain that allowed the battery to drain gets chewed out.

2.) The maintenance brings a mobile battery or connects a cable to the DC external connector

3.) A GPU is connected and brought on-bus (now there is electrical DC power) to charge up the battery through the ground service bus.

4.) The APU can only be started once there is enough charge in the battery - it can not be started on GPU power, for example (too much current).

In the IXEG case you can do three things: Either reload the aircraft or reboot gizmo - or use the "failures" window to recharge the battery.

Cheers, Jan

 

[vesalius]

OK, so all is as it should be then, great

Thanks for the explanation Jan!