Electrical Flashcards
How is DC power supplied?
Batteries (2 24v Main and Aux)
Transformer Rectifier (3)
How is AC power supplied?
IDG
APU
External Power
How is AC Standby Bus powered?
AC Transfer Bus 1
How is DC Standby Bus powered?
TR1 or TR2 or TR3
What converts DC power to AC power?
Static Inverter
What does turning on the BATT switch do?
Powers the Battery Bus, Switched Hot Battery Bus, and Standby Bus
(Hot always hot)
An illuminated Batt Discharge light means?
Main OR Aux battery is discharging
What will activate the TR Unit light ?
- Any TR failure on the ground
- TR1 failure in flight
- TR2 AND TR3 failure in flight
What Display Units are available if all generators are Inop?
Captains PFD and ND
Upper Display Unit
Purpose of Standby Power switch?
Controls Standby Buses
-Auto- switches to Batt if AC power lost
-Bat - hardwired to battery
Off - removes power from AC and DC Standby Buses
Used in total AC failure
Purpose of cross tie relay
Isolates DC buses
Will Open when:
-Bus Transfer Switch position to OFF
-During FD or AP ILS approach
What is the Automatic Generator On-line system?
Places both Generators on bus if APU fails as sole AC source while airborne
When would the GEN OFF BUS light illuminate?
When the generator isn’t powering the transfer bus
What is the APU load shedding logic?
-Automatically sheds the Main and Galley buses
-IFE buses also shed if required
What do the DRIVE lights indicate?
Drive is not producing power because:
- IDG failure
- engine shutdown
- IDG DISCONNECT switch
- IDG auto-decouple due to high oil temp
