Electrical Flashcards
Where are the batteries located?
- 1 located in aft equipment bay
- 1 located in nose compartment
How many batteries?
-2 nickel cadmium (nicad) batteries
What is the external power priority?
-the lowest priority
What is the purpose of the IDGs?
Converts variable N2 engine speed to 12,000 RPM generator speed
What does an IDG fault light indicate?
High oil temperature or low oil pressure within the IDG
AC Bus 1 priority system
- Generator 1
- APU generator
- Generator 2
- External power
AC Bus 2 priority system
- Generator 2
- APU generator
- Generator 1
- External power
When will AC ESS XFER switch light illuminate?
Anytime the AC BUS 1 is not powering the AC ESS BUS
Will the AC ESS XFER light illuminate with just the battery master switch on?
Yes
How many TRUs are there?
4
IDG overload protection
- 45 KVA for 5 mins
- 60 KVA for 5 seconds
When can the IDG be rest if it is disconnected?
Only on the ground after the engine is shut down
When will the AVAIL portion of the external power switchlight illuminate?
GPU plugged in with proper voltage, frequency, and phase (115v, 400hz, 3 phase)
What does pressing the external AC switchlight on the external panel do?
- Supplies external power to the aircraft in the service configuration
- Powers the AC service bus only
What are the 4 AC busses?
- AC bus 1
- AC bus 2
- AC ESS (essential) bus
- AC SERV (service) bus
If the AC ESS BUS is being powered by the ADG and a generator is brought back online, will the essential bus switch power sources?
No, the PWR TXFR OVERRIDE button must be pushed
When will the ADG deploy?
When AC BUS 1 and 2 are unpowered with weight off wheels
What will the ADG power?
Flaps, slats, pitch trim, hydraulic pump 3B, and AC ESS bus
With the ADG deployed when must the aircraft be configured by?
140 KIAS
Can the ADG be stowed inflight?
No
How many DC busses are there?
9
What is the purpose of the TRUs?
Converts 115v AC to 28v DC and 120 amps
What happens when the DC Service Switch is turned on?
The DC Service Bus is directly connected to the APU Battery Direct Bus
What is the main battery rated at?
24v 17 amp/hour
What is the APU battery rated at?
24v 43 amp/hour
What charges the main battery?
AC BUS 1
What charges the APU battery?
AC service bus
What happens when the battery switch is turned on?
Battery bus is directly connected to both the Main and APU Battery Direct buses
If all generators fail and the ADG is inop, how long can the batteries supply DC emergency power for?
Approximately 30 minutes
What supplies power to the fire extinguishers and hydraulic and fuel shutoff valves?
DC EMERG BUS
What happens when you turn the DC Service Switch on?
Directly connects the DC SERV BUS to the APU BATT DIR BUS
