Electrical Flashcards
(25 cards)
How many generators (including APU) can power all electrical needs?
1
In flight, during generator failure, what is automatically shed?
Main galley power
What is the main difference between when Gen 1 fails versus Gen 2?
Gen 1 is connected to the Essential Bus and Shed while Gen 2 requires the AC ESS FEED button depressed
When RAT deploys, what does it power?
AC and DC ESS BUS and SHED
In an emergency what does BATT 1 power?
AC ESS BUS through inverter
In an emergency what does BATT 2 power?
DC ESS BUS
What are the electrical priorities?
G enerators E xternal Power A pu generator R am air turbine B atteries
What are the capacities of the generators and the APU?
90 KVA
3 phase
115-200 V
400 Hz
What are the capacities of the emergency generator?
5 KVA
3 phase
115-200 V
400 Hz
What do the (TR) transformer-rectifiers do?
Convert AC to DC
When will you see a green arrow connected to the battery?
only when current is >1 amp
What are the limitations for the IDG FAULT buttons?
Do not depress more than 3 seconds.
Engine must be running or windmilling
Can be reset on ground only
When will you get the IDG FAULT light on?
High IDG oil temp
Low IDG oil pressure
When will the batteries start charging?
<26.5V
When will the battery contactors close?
AC BUS 1&2 not powered by other sources (no EMER GEN during flight, worst case)
When will the auto batt cut-off?
Ground BAT in AUTO AC power source N/A Batt voltage low (reset by cycling BAT buttons)
How long are batteries prevented from charging after APU start?
30 minutes
During preflight, what white lights should be present on the ELEC panel?
None!
When you turn on the battery what is the max charging current allowed?
<60A and decreasing within 10 seconds
What tells you that the APU is powering the AC?
AVAIL light on the APU START button AND AVAIL light on the EXT POWER button
When you start engine 2, what happens to the bus tie?
Opens, APU now powers BUS 1 and Generator powers BUS 2
RAT & EMER GEN FAULT light is on, what does this mean?
The RAT takes 8 seconds to spool up before coming on-line, during this time you are running off the batteries.
What is the min speed for the RAT to function?
140kts
During landing, at what speed does the EMER GEN become unavailable?
125kts
