24 Electrical Flashcards
What does the “External Power Available” light indicate?
External power in the proper phase sequence is available.
What is the source of power for the emergency power distribution system on a lost of all generator scenario?
The batteries for 30 minutes.
Which electrical component maintain generator output frequency at 400 CPS?
The Constant Speed Drive.
What component is installed bw the LT and RT AC elect sys that allows one sys to pw the opposite system?
The AC crosstie relay
What is the function of the GCR?
It control each gen field, thereby controlling the generator ‘s ability to produce current. (14.24.2.6)
When are the two occasions the GCR will open?
AC power fault protection logic and if the ENG FIRE shutoff handle is pulled. (14.24.2.6)
Which electrical components supply pw to high-current draw items?
The Generator buses.
Where is the APU pw relay?
Between the APU generator and each generator bus.
What annunciator message will illuminate when a generator relay is open?
R/L GEN OFF
What is the purpose of the GROUND SERVICE ELEC PWR panel (switches)?
It connects the APU or external power to the Ground Service Bus when the Ground Service Bus is not powered by the right Generator Bus. (14.24.5.10)
Can you power the ground service bus and the DC Transfer bus with both of the sw turned on at the same time?
No, one sw deactivate the other-one. (14.24.5.10)
What are some of the items powered by the AC Emergency Bus?
CA horizon and heading display, Altimeter FO compass display and VHF Nav 1.
What items are powered off the Battery direct bus?
B-Battery charger R-Refueling panel control and valves A-Aircraft Clock C-Charger and transfer relay E-Emergency Inverter/DC Emer Bus S-FWD Stairs if instaled
When the battery is turned ON. What items are powered off the Battery Bus?
A-APU control A-APU EGT A-AC Emergency bus OFF light D-DC Emergency bus OFF light D-DC Transfer bus OFF light
Once power is established on the DC Transfer Bus; What items are powered out the DC transfer Bus?
S A F E S *
