Engine electrical systems Flashcards
How would you see newly installed generator brushes to the commutater
The brushes must be shaped to provide an area of maximum contact with the commutator
To see the brushes, use a fine grade sandpaper placed around the commuter with the sanding surface facing outward. Turn the amateur in a normal direction of rotation until the face of the brushes is properly contoured. Remove the sandpaper and blow out any residual with a compressed air
When is it necessary to replace the brushes in a starter
When they are 1/2 their original length
Where is the generator rating and performance data located
On the data plate attached to the generator
What unit makes up a DC generator three unit regulator
The voltage regulator, current limiter, and reserve current cut out
What method is used to control the voltage of an aircraft alternator
A voltage regulator
What determines the frequency of the voltage of an alternator
Frequency depends on the speed of rotation of the rotor and the number of polls
How is alternator frequency maintained
By installing a constant speed Drive unit between the engine and alternator
What is the three basic types of DC motors
Series motor, shunt motors, and compound motors
Name the parts of a DC motor
Amateur, brushes, commutator and field frame (ABC-F)
Why is a starter generator system, used on many turbine engine’s
To save space and weight
The starter generator operates as a starter motor during engine starting. After the engine has reached a self-sustaining speed it switches operation to a generator for a supply AC electrical power for Aircraft systems
Why should stranded wire be used in power plant applications
It is less likely to fatigue and break from vibrations
What is the American wire gauge system of designating electrical wire size
A cage number is assigned to the wire according to its cross-sectional area. The smaller the gauge number the larger the wire
What is open wiring
Any wire, wire group, or wire bundle not enclosed in conduit
What message are used to control the voltage output of a DC Aircraft generator
The vibrating type voltage regulator, three unit regulator, and carbon pile
The only practical means of regulating generator voltage is to control the strength of the magnetic field. Field strength is determined by the amount of current flowing through the field coils, and the current is controlled by placing some of variable or intermediate resistance in the external field circuit of the regulator
What aircraft electrical system normally doesn’t have a fuse or circuit breaker
They start circuit
