Electrical Systems Flashcards
What is voltage?
Electrical force that causes current to flow. Measured in volts.
What is the safety concern with electricity?
Electrical shock disrupts the body’s normal electrical function. Could stop the heart, lungs or both causing injury or death.
What is current?
Movement of electrical charge through a circuit. measured in amperes.
What is resistance?
The opposition to the flow of electricity. it controls the amount of voltage and current. measures in ohms.
What is Hertz?
the electrical unit of frequency. 1 Hertz equals 1 cycle per second.
What is a bus?
A distribution point thats connected to the battery and generator. Components derive their power from the bus.
What engines have a generator?
Engines 2, 3 and 4.
What is different about the APU generator?
It has a cooling bell housing.
What are relays used for?
They connect and control power to the buses.
What is special about sensing relays?
They are interchangeable and identical. they do not energize unless the generator voltage and frequency are correct.
Where are the sensing relays located?
The main and forward load centers.
What type of circuit breakers are used and for what?
Push-pull type. They are used to protect electrical circuits.
How many Voltage Regulator and Supervisory Panels are there and where are they?
4, in the main load center.
What does a VR/Supervisory Panel do?
protects the generators from under/over voltage, under/over frequency and feeder faults.
Are VR/Supervisory Panels interchangeable?
Yes, they are identical.
