Electrics

Question 1

What equipment can provide 28V DV?

Answer 1

2 NiCad Batteries (Main and Aux.); 2 Starter/Generators; 2x Transformer Rectifier Units (TRU’s); Also, on ground: GPU and APU

Question 2

Voltage and Ampere Rating for Batteries

Answer 2

2x 24V batteries rated 40 amp/hr (Sufficient for 30 minutes)

Question 3

Minimum Voltage for Start

Answer 3

22V

Question 4

Systems directly powered by the Main Battery (Batt Bus)

Answer 4

• 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

Question 5

Can the ESS BUS power the L and/or Main BUS?

Answer 5

No, a diode prevents it from doing so

Question 6

What does the Battery Master do?

Answer 6

Connects Main and Aux Batteries to the Essential Bus

Question 7

What does the MAIN BATT switch do?

Answer 7

Connects Main Battery to the Right Main Buses

Question 8

What does the AUX BATT switch do?

Answer 8

Connects the Aux Battery to the Left Main Bus to enable charging when the Generators are on line

Question 9

Can the Aux Battery Power the Left Main Bus?

Answer 9

No, a diode prevents it from doing so

Question 10

What does the MAIN BUS TIE do?

Answer 10

Closes the Main Bus Tie to power the Left Main Bus

Question 11

How many temperature sensors does each battery have?

Answer 11

2

Question 12

Battery Hot Warning is presented when the temperature of the battery exceeds:

Answer 12

65°C

Question 13

Where is the DC generator mounted?

Answer 13

On the Accessory Gearbox of each engine

Question 14

DC Generator Output and Rated Amps

Answer 14

28V, 200A on the ground, 300A in the air

Question 15

DC Generators Max Load according to instrument read outs on ground/inflight

Answer 15

• Ground Ops: 0.7
• In Flight: 1.0

Question 16

What happens to DC Generators when External Power is connected?

Answer 16

DC Generators automatically disconnect when external power is connected

Question 17

What pilot action is required for a ‘MAIN BATT HOT” warning light and temp monitor confirms overheat?

Answer 17

Battery (Affected) OFF. If temperature continues to rise, land immediately at nearest suitable airport.

Question 18

What is the fixed AC system primarily used for? How many inverters are required to power the fixed AC system?

Answer 18

Nav Instruments. 1 inverter required.

Question 19

When the Battery Master is selected ON, which bus(es) will be powered?

Answer 19

Essential Bus, Fixed AC Bus (Through the inverter)

Question 20

What selections are available for the AUX inverter?

Answer 20

L OFF R

Question 21

Which lights are directly powered by the battery power bus (Hot Battery Bus)?

Answer 21

Flight Compartment dome lights, Boarding Lights

Question 22

How many batteries does the aircraft have? Voltage?

Answer 22

2x 24V, Rated for 40 Amp Hour

Question 23

Which buses are powered with:

• Battery Master On?
• and Main Battery switch On?
• and with the Main Bus Tie also turned on?

Answer 23

• With Batter Master ON: Essential Bus and Fixed AC Bus
• Right Main Bus
• Left Main Bus

Question 24

How do we get bettery power to the Left Main Bus?

Answer 24

Battery Master On, Main Battery On, Main Bus Tie On

Question 25

What voltage should we see on the DC monitor with DC External power on?

Answer 25

28 Volts

Question 26

Which buses will be powered with DC external power suppling the Aircraft?

Answer 26

Essential Bus, Left and Right Main Bus, Fixed AC Bus, Left and Right Secondary Bus; DC BUS Closes