Aircraft Electrical Systems Flashcards
What controls the output voltage of an alternator?
The GCU (Generator Control Unit).
How long should bonding jumper wires be?
As short as practicable but long enough to allow free movement of the component.
What factors are considered when selecting wire size for electrical power?
Permissible voltage drop, the system voltage, wire lenght, current carrying and if the load is continuous or intermitent.
How can a particular wire in a bundle be identified?
By the identification code on the wire
What tool would you use to determine the SIZE of an unmarked wire?
A Wire Gauge
What size electrical conduit should be used?
25% larger than the maximum diameter of the wire bundle.
What should be done to a conduit when fittings are not used?
It should be deburred to prevent insulation damage.
What hardware is used to make bonding or grounding connections to a structure of dissimilar material?
A washer of suitable material should be used so that corrosion will occur on the washer.
How many terminal lugs can be put on a single terminal strip stud in an aircraft?
Four
When do DC motors draw several times their rated current?
When starting.
When is a circuit breaker designed to open?
When an overload or circuit fault exists and before the wire emits smoke.
What type of circuit breaker should not be used in aircraft?
Automatic reset-type circuit breakers.
What color is a left and right wingtip position light?
Left - Red / Right - Green.
Where is the White position/ navigation light mounted?
On the tail, visible from the rear.
What could cause an AC electric motor to run too fast?
Excessive applied VOLTAGE or shorted field windings.
What tool is used to check a motor or generator armature for shorts and opens under load conditions?
A Growler
When using a Growler, what indication will occur when a short exists between an armature segment?
When a metal blade is held over the armature and a short exists in a segment, the blade will begin to vibrate and chatter.
How is the output voltage of an alternator controlled?
By varying the field CURRENT that excites the alternator.
What instruments are used to monitor electrical system loads?
Ammeteres and voltmeters.
What would it be necessary to analyze an electrical system before increasing the load on the system?
To determine the generator capacity, wire size, and protective device capacity will not be exceeded.
Name several types of electrical devices that would be considered intermitent loads on an electrical system:
Landing gear, cow/ and wing flap motors, radio transmitters.
Under what conditions must a switch be derated from its nominal rating?
When used with inductive circuits, circuits with high in-rush current, and with DC motors.
At what point in a circuit should the protective device be located?
As close the source as possible.
What could cause an AC electric motor to run too slowly?
Lack of lubrification, defective wiring or low voltage.
Prior to making a continuity check, what must be done to an electrical circuit?
The power must be turned off.
