Thank you so much
Lancelot de Boyles and
NSEU. I really appreciate your teachings
I'm taking this to mean that the meter is measuring at a point where there is no load, and so no attempt is made to measure/display amps.
To measure amps requires a load.
So does this mean with normal AC power available & powering the aircraft, BAT BUS is not powering any equipments???. I am not sure of this because, recently in the sim, we had multiple amber lights on the overhead panel (with no indication on the electrical panel of any failure) with normal AC power available. Later on after the session was over, our examiner told us this was a battery bus failure.
You are starting the APU on battery power. It's a given that there is a significant draw, and that this is normal in this circumstance-
Battery as only source of power
Deliberate APU start
Not abnormal
Thank you very much this makes sense
When are you testing the voltage/current in this situation? What power source is on the aircraft?
I am not testing the voltage but was just curious why is there no amperage indication, it does not even show ZERO, the indication is blank.
The aircraft is running with normal AC power sources from its respective IDGs . This question is w.r.t NGs
My questions here: I understand there is no load on the battery bus, thus no amperage. But why is this the case? With normal AC power available, isn't the BAT BUS supplying its respective systems. I have had a situation in the SIM with BAT BUS failure & normal AC power available and not failed (informed to us later on by the examiner that this was an example of BAT BUS failure after the sim session was over) we had multiple system failures. So I am under the assumption that BAT BUS still powers many systems even with AC power available and supplying the aircraft and thus there has to be a load/ampergae indication
Regarding the Caution light, (EDIT), on the NG wiring schematic 24-31-11, a wire is shown going from the APU ECU to the P5 (overhead) panel. When the APU is started, a signal on this wire stops the CAUTION ouput from the panel.
Thanks NSEU this makes sense