Electrical Flashcards
What size generator must be used in an aircraft electrical system if the connected electrical load is 30 amps, and there is no way of monitoring the generator output?
When monitoring is not practical, the total continuously connected electrical load must be no more than 80% of the rated generator output. This would require a generator with a rating of 37.5 amps. Practically, a 40- amp generator would be installed.
What is meant by “flashing” the field of a generator?
Restoring the residual magnetism to the frame of the generator. This is done by passing battery current through the field coils in the direction it normally flows when the generator is operating.
What is meant by paralleling the generators in a multi-engine aircraft?
Adjusting the voltage regulators so all the generators share the electrical load equally.
What are three types of voltage regulators used with aircraft generators?
Vibrator-type, carbon-pile type, and solid state-type.
What is meant by a trip-free circuit breaker?
A circuit breaker that cannot be closed while a fault exists, regardless of the position of the operating handle.
What is meant by a slow-blow fuse?
A fuse that will allow more current than its rating to flow for a short period of time, but will open the circuit if more than its rated current continues to flow.
What is the function of a fuse or circuit breaker in an aircraft electrical circuit?
It protects the wiring from an excess of current. It will open the circuit if enough current flows to heat the wire.
What are two principles upon which circuit breakers operate?
Magnetic circuit breakers open a circuit when the current creates a strong enough magnetic field. Thermal circuit breakers open a circuit when the current causes enough heat.
What circuit in an aircraft electrical system is not required to have a circuit protective device?
The main circuit for starter motors, used during starting only.
Is an automatic-reset circuit breaker approved for aircraft electrical circuits?
No, a manual operation is needed to restore service after the circuit breaker has tripped.
How does a vibrator-type voltage regulator maintain a constant voltage?
When the voltage rises above the desired value, an electromagnetic relay opens and inserts a resistor in the generator field circuit, decreasing the field current and lowering the generator output voltage.
What two components are normally housed with a vibrator voltage regulator in a single-unit generator control?
A current limiter and a reverse-current cutout relay.
What are the colors and positions of aircraft position lights?
- Left side/wing tip-red
- Right side/wing tip-green
- Aft-white
What is the purpose of wing inspection lights?
To permit visual detection of ice formation on wing leading edges while flying at night.
