AIRCRAFT ELECTRICAL SYSTEMS

Question 1

What controls the output voltage of an alternator?

Answer 1

The GCU (Generator Control Unit).

Question 2

How long should bonding jumper wires be?

Answer 2

As short as practicable but long enough to allow free movement of the component.

Question 3

What factors are considered when selecting wire size for electrical power?

Answer 3

Permissible voltage drop, the system voltage, wire lenght, current carrying and if the load is continuous or intermitent.

Question 4

How can a particular wire in a bundle be identified?

Answer 4

By the identification code on the wire.

Question 5

What tool would you use to determine the SIZE of an unmarked wire?

Answer 5

A Wire Gauge

Question 6

What size electrical conduit should be used?

Answer 6

25% larger than the maximum diameter of the wire bundle

Question 7

What should be done to a conduit when fittings are not used?

Answer 7

It should be deburred to prevent insulation damage.

Question 8

What hardware is used to make bonding or grounding connections to a structure of dissimilar material?

Answer 8

A washer of suitable material should be used so that corrosion will occur on the washer.

Question 9

How many terminal lugs can be put on a single terminal strip stud in an aircraft?

Answer 9

Four

Question 10

When do DC motors draw several times their rated current?

Answer 10

When starting

Question 11

When is a circuit breaker designed to open?

Answer 11

When an overload or circuit fault exists and before the wire emits smoke.

Question 12

What type of circuit breaker should not be used in aircraft?

Answer 12

Automatic reset-type circuit breakers.

Question 13

What color is a left and right wingtip position light?

Answer 13

Left – Red / Right – Green.

Question 14

Where is the White position/navigation light mounted?

Answer 14

On the tail, visible from the rear.

Question 15

.What could cause an AC electric motor to run too fast?

Answer 15

Excessive applied VOLTAGE or shorted field windings.

Question 16

What tool is used to check a motor or generator armature
for shorts and opens under load conditions?

Answer 16

A growler

Question 17

When using a Growler, what indication will occur when a short exists between an armature segment?

Answer 17

When a metal blade is held over the armature and a short exists in a segment, the blade will begin to vibrate and chatter.

Question 18

How is the output voltage of an alternator controlled?

Answer 18

By varying the field CURRENT that excites the alternator.

Question 19

What instruments are used to monitor electrical system loads?

Answer 19

Ammeters and voltmeters

Question 20

Why would it be necessary to analyze an electrical system before increasing the load on the system?

Answer 20

To determine the generator capacity, wire size, and protective device capacity will not be exceeded.

Question 21

Name several types of electrical devices that would be considered intermitent loads on an electrical
system:

Answer 21

Landing gear, cowl and wing flap motors, radio transmitters

Question 22

Under what conditions must a switch be derated from its nominal rating?

Answer 22

When used with inductive circuits, circuits with high in-rush current, and with DC motors.

Question 23

At what point in a circuit should the protective device be located?

Answer 23

As close the source as possible.

Question 24

What could cause an AC electric motor to run too slowly?

Answer 24

Lack of lubrification, defective wiring or low voltage.

Question 25

Prior to making a continuity check, what must be done to an electrical circuit?

Answer 25

The power must be turned off