Aircraft electrical system Flashcards
What is the purpose of a circuit breaker
Protect the circuit and wires from fire. The circuit breaker opens the circuit when an overload exists
What are the two principles on which circuit breakers operate
Thermal a magnetic
What tool is used to measure the size of unmarked electrical wires
A wire gauge
What are the colors of an aircraft position lights and where are they mounted
Green light right wingtip red light left wingtip white light in a position where is visible from the rear of the aircraft
What are the factors to be considered when selecting wire size for an electrical power
One factor is allowable power loss In the line. A second factor is the permissible voltage drop in the line and the third factor is the current caring ability of the conductor
When is a circuit breaker a fuse design to open the circuit
Before the conductor in mid smoke. To accomplish this the current characteristics of the protected device Must fall below that of the associated conductor
What type of breakers are not acceptable for use in aircraft
Auto reset breaker’s
What is a slow blow a fuse
If use to compensates for surges in high in rush current by not blowing for several milliseconds
What are the three most common fault that occur in an electrical circuit
Short circuit, open circuit, low power
What size electrical conduit should be used for a specific cable bundle
Conduit should have an inside diameter that is 25% larger than the maximum diameter of the conductor bundle
What color insulator on a solderless connector is proper for a 10 gauge wire
Yellow
How should electrical switches typically be oriented in the on portion
Upper or forward
When should electrical switches be derated from their normal current rating
Russian circuits such as circuits containing indicates lamps, and inductive circuits that have magnetic energy stored in the solenoid coil’s, or relays, and for DC motor circuits, which draws several times they’re rated current during starting
When do DC electric motors drawl several times they’re rated current
During starting
How should electrical switches typically be oriented in the On position
Upper Or Forward
What would cause an AC electrical motor to run too fast
And excessive supply voltage, or the motor field windings shorted
What would cause an AC electrical motor to run to slow
Low applied voltage, defective wiring, or no lubrication
How is the output voltage of an alternator controlled
By using a voltage regulator to control the exciter field current and dust regulate the exciter output voltage applied to the alternator field
What should be checked before any aircraft electrical load is increased
The associated wires, conductors, and circuit protection devices should be checked to determine that the new load will not exceed the rated limits of these units
What is the main advantage of using a AC for Aircraft electrical power Systems
The principal advantage is that the voltage of AC power systems is easily changed by the use of a transformer. Therefore, you can transmit power at high-voltage and low current and thus reducing the size and weight of the wire in the circuit
In AC power system how is DC obtained for battery charging
The alternating current is changed to direct current by the use of the rectifier
What warns pilots Of overheating batteries
The thermal sensor in the battery and a light in the cockpit
How long should bonding jumper wires be made
Large enough to handle all the return current flow in a short as possible to prevent an increase in resistance
What are the two items that wear on a starter generator
Commutator And the brushes
What power is the ELT
The ELT battery power
