6 - Electrical Flashcards
On the electrical panel. What does the “battery discharge” light signify?
An excessive battery discharge is detected
On the electrical panel. What does the TR UNIT light signify
A: On the ground
B: In the air
A: Any TR has failed
B: TR1 or TR2&TR3 has failed
On the electrical panel, what does the ELEC light mean.
Will it display while airborne?
Fault in DC or Standby system. Shows only on the ground
On which bus is the Recirc fans connected
Connected to the bus controlled by the CAB/UTIL switch
The DRIVE light signifies what exactly?
Low oil pressure in the IDG
What is the nominal hz and voltage for the AC system
115+/-5, 400+/-10
Which 3 categories is the electrical system divided into
AC power, DC power, Standby power
Under what circumstance does the automatic generator on-line feature work?
If the APU shuts down, or fails, during/after take-off, with the APU powering both transfer buses, the engine generators are placed online.
Only once per flight.
During single generator operation, what is the sequence of load shedding?
Galley and mainbus on transfer bus 2 first, then on transfer bus 1, then the IFE.
What happens if the APU is the only source of power in flight?
Will the same happen on the ground?
All galley busss and main buses are automatically shed.
On the ground the APU will try to carry the entire electrical load.
What is the battery voltage range?
26 +/- 4
TR1 and TR2 are connected to their respective transfer buses, but what is the normal supply for TR3?
Transfer bus 2
During normal non-approach operations, what does TR1 and TR2 power?
DC bus 1, DC bus 2, DC Standby bus
TR3 normally powers what?
The battery bus
DC bus 1 and DC bus2 are isolated when?
Automatically at glide slope capture during a FD or AP ILS approach. Or when the bus transfer switch is off
