Engine Electrical Systems Flashcards
When the engine is operating what does an ammeter / loadmeter indicate when connected to:
1 – Battery positive lead
2 – Generator output lead
Battery positive lead – The ammeter indicates whether the battery is charging or discharging.
Generator output lead – Indicates the current produced by the generator or electrical system load
What is done to ensure that each generator shares the load in a multiple generator system
The generators are paralleled
Where would you find generator rating and performance data
On generator data plate
How is the voltage of a DC generator controlled
Varying the field CURRENT strenght
What is the most common type of alternator used in most aircraft AC systems
The three phase alternator
How does a voltage regulator control the voltage of an alternator
By regulating the VOLTAGE output of the DC exciter
What does the speed of rotation and number of poles of an alternator determine
The FREQUENCY of the alternator output
What are some methods used to maintain 400 Hz alternator output frequency on large turbojet or turbofan engines
CSD, IDG and VSCF variable-speed constant frequency power systems
Name the major parts of a DC motor
The armature, field, brushes and frame assembly
Name the components of a direct cranking electric starter system
An electric motor, reduction gears and an automatic engaging and disengaging mechanism
Name three types of DC motors
Series, Shunt (parallel) and Compound
What type of DC motor is commonly used for a reciprocating engine starter and why
A Series Wound Motor – Has a high starting torque under havy load conditions
What are the operating modes of a turbine engine starter generator
First as a Starter, then as a generator once the engine is running
What is a possible indication when a starter drags
A noisy, dirty , worn starter commutator
Where would wire with high temperature insulation material be used
When they run close to high temperature areas such as exhaust stacks or heating ducts
