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 CURRENT to the field
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 (integrated drive generator; a csd integrated with a generator)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.
