Electrics Flashcards
What equipment can provide 28V DV?
2 NiCad Batteries (Main and Aux.); 2 Starter/Generators; 2x Transformer Rectifier Units (TRU’s); Also, on ground: GPU and APU
Voltage and Ampere Rating for Batteries
2x 24V batteries rated 40 amp/hr (Sufficient for 30 minutes)
Minimum Voltage for Start
22V
Systems directly powered by the Main Battery (Batt Bus)
- Engine fire Extinguishers;
- APU Fire Extinguishing;
- Fuel and Hydraulic Shut Off Valves;
- Refuel/Defuel Shut Off Valve;
- Flight compartment dome lights;
- Boarding lights;
- PA emergency power
Can the ESS BUS power the L and/or Main BUS?
No, a diode prevents it from doing so
What does the Battery Master do?
Connects Main and Aux Batteries to the Essential Bus
What does the MAIN BATT switch do?
Connects Main Battery to the Right Main Buses
What does the AUX BATT switch do?
Connects the Aux Battery to the Left Main Bus to enable charging when the Generators are on line
Can the Aux Battery Power the Left Main Bus?
No, a diode prevents it from doing so
What does the MAIN BUS TIE do?
Closes the Main Bus Tie to power the Left Main Bus
How many temperature sensors does each battery have?
2
Battery Hot Warning is presented when the temperature of the battery exceeds:
65°C
Where is the DC generator mounted?
On the Accessory Gearbox of each engine
DC Generator Output and Rated Amps
28V, 200A on the ground, 300A in the air
DC Generators Max Load according to instrument read outs on ground/inflight
- Ground Ops: 0.7
- In Flight: 1.0
What happens to DC Generators when External Power is connected?
DC Generators automatically disconnect when external power is connected
What pilot action is required for a ‘MAIN BATT HOT” warning light and temp monitor confirms overheat?
Battery (Affected) OFF. If temperature continues to rise, land immediately at nearest suitable airport.
What is the fixed AC system primarily used for? How many inverters are required to power the fixed AC system?
Nav Instruments. 1 inverter required.
When the Battery Master is selected ON, which bus(es) will be powered?
Essential Bus, Fixed AC Bus (Through the inverter)
What selections are available for the AUX inverter?
L OFF R
Which lights are directly powered by the battery power bus (Hot Battery Bus)?
Flight Compartment dome lights, Boarding Lights
How many batteries does the aircraft have? Voltage?
2x 24V, Rated for 40 Amp Hour
Which buses are powered with:
- Battery Master On?
- and Main Battery switch On?
- and with the Main Bus Tie also turned on?
- With Batter Master ON: Essential Bus and Fixed AC Bus
- Right Main Bus
- Left Main Bus
How do we get bettery power to the Left Main Bus?
Battery Master On, Main Battery On, Main Bus Tie On
What voltage should we see on the DC monitor with DC External power on?
28 Volts
Which buses will be powered with DC external power suppling the Aircraft?
Essential Bus, Left and Right Main Bus, Fixed AC Bus, Left and Right Secondary Bus; DC BUS Closes
