Electrical Flashcards
Main battery Amp? Voltage?
17 Amp & 24 V
APU Generator Amp? Voltage?
43 Amp & 24V
What are the 4 AC BUSs
AC BUS 1
AC BUS 2
AC ESSENTIAL BUS
AC SERVICE BUS
What does the AC AVAIL/IN USE switch-light do?
AVAIL (green) indicates external power is connected and ready to use IN USE (white) indicates that the external AC power is supplying the electrical system
What is the purpose of the IDG 1 & 2, gaurded, switch-lights?
used to disconnect IDG (integrated engine driven generator) from engine (white light means successful disconnect. FAULT light (amber) indicates a fault within the system. (High oil temp/ low oil pressure)
What does the AC ESS XFER (white) switch-light mean?
Indicates that essential bus is being powered by AC BUS 2. This automatically happens during a Bus 1 failure
What position should (in normal operations) the GEN 1 & 2 switches be in?
AUTO- this connects the generator to the associated bus.
OFF/RESET disconnects or resets the generator from the GCU (generator control unit)
What does the FAIL (amber) light mean on the AUTO XFER switch-light mean?
indicates a fault preventing autotransfer
What is the bus priority for AC BUS 1? AC BUS2?
- GEN 1
- APU GEN
- GEN 2
- External Power
(goes the other direction for BUS 2)
How long are the batteries good for in emergency operation?
30 minutes
What is the minimum volts the APU battery & Main battery should show?
22V
What does the Battery Master Switch do?
Connects the APU battery and Main Battery to the Battery Bus
What does the DC SERVICE switch do?
Connects the DC service bus to the APU battery direct bus (powers Nav’s, Lav’s, & Dome’s)
What causes a generator or the APU to be tripped off & removed from the BUS?
Over/under voltage or Frequency
Overcurrent
Out of phase
On the ground with only battery power available, why is operating time limited?
5 min. due to the fans used to cool EICAS displays are AC powered and not operating yet.
How many TRU’s are on the CRJ 700/900?
4 TRUs (Transformer Rectifier Unit)
What is each TRU rated at?
supplies 115 VAC power to create 28 VDC unregulated power. max rated at 120 amps.
A Fault resulting in the loss of AC BUS 1 will result in loosing how many TRU’s?
1
What amount of power do the IDG’s produce?
115 VAC
400Hz
3 phase electrical power
rated at 40 kVA
When does the ADG automatically deploy?
AC BUS 1 & 2 are unpowered
No weight-on-wheels signal
aircraft generator was the last power source
what does the ADG provide?
115 VAC
400 Hz 3 phase
rated at 15 kVA
At what airspeed does the ADG not supply power any more?
below 135 KIAS
