What is the function of circuit breakers in the aircraft electrical system?

What is the function of circuit breakers in the aircraft electrical system?

• A. Provide protection from overloads and allow manual isolation of faulty circuits.
• B. Act as fuses that burn out on overload.
• C. Increase system voltage to buses.
• D. Store energy for DC loads.

Answer: (A)

Circuit breakers protect wiring and equipment by interrupting current when a fault occurs and by giving you a way to disconnect a circuit for safety or maintenance. They sense excessive current—whether from an overload or a short circuit—and trip to open the circuit, preventing damage or fire. After the fault is cleared, they can be reset, restoring power without needing a new part. This resettable, isolating capability is what sets breakers apart from fuses, which burn open and must be replaced. They do not raise system voltage or store energy for loads.

Circuit breakers protect wiring and equipment by interrupting current when a fault occurs and by giving you a way to disconnect a circuit for safety or maintenance. They sense excessive current—whether from an overload or a short circuit—and trip to open the circuit, preventing damage or fire. After the fault is cleared, they can be reset, restoring power without needing a new part. This resettable, isolating capability is what sets breakers apart from fuses, which burn open and must be replaced. They do not raise system voltage or store energy for loads.