Electrical System Flashcards
What is the electrical rating of the IDG’s?
115V, 400 Hz, 3 phase 40kVA
What is the function of the integrated drive mechanism?
Hydro-Mechanical device that is driven by the variable-speed engine accessory gearbox which uses an integral oil system to drive the generator at a constant speed
What does the FAULT light on the IDG switchlight mean?
Indicates that either the IDG oil has overheated or the is oil pressure is low
What does DISC mean on the IDG switchlight mean?
The electrical solenoid has been energized to cause the IDG to disconnect from the accessory gearbox
What happens if the disconnect solenoid does not work on the IDG?
The gear will shear off of the accessory gearbox resulting from the Constant Speed Drive exceeds a predetermined temperature or an over-torque situation
What busses are powered when the IN USE button is pressed on the AC external services panel?
only the AC Service Bus. You will also see “SERVICE CONFIGURATION” on the upper left part of the AC synoptic page
What will you get when you switch on the DC Service switch? What battery is it connected to?
The passenger cabin lights, and the nav lights. It is connected to the APU Battery Direct Bus
What are the 4 busses on the AC electrical system?
AC Bus 1
AC Bus 2
AC Essential Bus
AC Service Bus
What is the function of the AC ESS XFER switchlight located on the Electrical Power Control Panel?
It illuminates to indicate that the AC Essential Bus has either automatically or manually been transferred from AC Bus 1 to AC Bus 2
What conditions must be met for the ADG to automatically deploy?
- AC Bus 1 and 2 power sense inputs falls below 50 volts
- No WOW
- Any aircraft generators were on line for at least 3.45 seconds prior to the loss of power on AC Buses 1 and 2
What does the FAIL portion of the Auto XFER Inhibit switchlight indicate?
It means that the auto transfer system stopped the auto transfer of AC Bus 1 or 2 due to a fault on the bus
What does the OFF portion of the Auto XFER Inhibit switchlight indicate?
The auto transfer system was manually inhibited
What lights will illuminate after a complete failure of AC Bus 1?
The AUTO XFER Fail switchlight, and the AC ESS XFER
What buses are powered by the ADG?
- ADG Bus
- AC Essential Bus
- ESS TRU 1
- DC Essential Bus
- DC Battery Bus
- DC Emergency Bus
- Main Battery Direct Bus
- APU Battery Direct Bus
What does the power transfer override switch located on the ADG deploy handle do?
It transfers the AC Essential Bus back to a normal AC power source
What does a TRU do?
Converts AC into DC
What is the power output of the TRU’s
28VDC and 120 amps
How many TRU’s are installed on the CRJ-700?
4
What are the 9 buses powered by the DC system?
- DC Bus 1
- DC Bus 2
- DC Essential Bus
- DC Service Bus
- DC Utility Bus
- DC Battery Bus
- DC Emergency Bus
- Main Battery Direct Bus
- APU Battery Direct Bus
What sources power the Main and the APU batteries?
AC Bus 1 charges the main battery, and the AC Service Bus charges the APU Battery
Which buses are the batteries capable of powering?
- Main Battery Direct Bus
- APU Battery Direct Bus
- DC Battery Bus
- DC Emergency Bus
- DC Essential Bus (in flight only)
What is the function of the DC Emergency Bus?
It provides power to the engine and APU fire extinguishers, fuel and hydraulic shutoff valves
When is the DC Emergency Bus displayed on the DC synoptic page?
When either one of the power sources (DC Battery Bus and APU Battery Direct Bus) to it is lost, or the DC Emergency Bus itself fails
What displays are powered when the battery master is selected on and it is the only source of electricity?
ED 1, ED 2, ISI, and the BTU (RTU)
What extra instrument is powered when only the battery master is on and it is the only source of electricity in flight?
Left PFD
