Electrical Flashcards
Components of the electrical system
Starter Generator
Generator
Battery
EPS
Inverters
Busses
GPU
Generator 1 stats
28v/300a
What primary function does gen 1 provide?
Starter generator (-45 AC)
What busses are powered by gen 1?
Gen 1
Gen 1 bus
Avionics 1/2
Battery
Standby
Non Essential bus
Gen 2 stats
28v/115a
Can Gen 2 carry the entire AC electrical load?
No
What busses does Gen 2 provide under normal conditions?
Gen 2 bus
Addl battery (if installed)
What maintains constant loads and voltage for the generators in normal ops?
GCU (Gen control units)
What does the auxiliary DC system power?
6 cabin outlets for pax use
Battery stats
24v/40a
What can the battery power and for how long?
Essential avionics for 30 minutes below 50a and 20 minutes below 60a
EPS stats
24v DC/5a
What is the GPU set to when connected?
800-1000a
What inverter is operating when the overhead switch is set to Batt?
Gen 1
What inverter is operating when the overhead switch is set to Gen 1?
2
Gen 1 max load
300a or 450a @ 2 min/hour
Light switch on stairs is on what bus?
Hot battery bus
Where are the autopilot CBs located?
Avionics bus 2, co pilots panel
Where are the pitch trim servo CBs located?
Stab trim…batt bus, pilots side
What do red/amber CAWS bus messages indicate?
Low voltage at the bus
Amber battery CAWS message means….
60+ amp draw on the battery
What does green AVAIL light indicate on the GPU button?
28v available
What prevents the AC generators from connecting to the system at the same time GPU is connected?
Generator disconnect relay
Which CBs may be reset once while inflight?
Battery bus
Avionics 1
26 VAC
What are the conditions of resetting a CB inflight?
Only once
Wait one minute from trip
No burning smell
What happens in the system when Gen 1 fails?
Gen 2 BTB closes
Non ESS BTB opens
What major systems are on the non-essential bus?
Landing gear
Anti ice
How would you lower the gear with a Gen 1 failure?
Non essential bus switch to override
