What component protects wiring from excessive current in the instrument lighting system?

In the context of an instrument lighting system, a component that protects wiring from excessive current is a circuit breaker. Circuit breakers are designed to detect overload conditions and automatically interrupt the flow of electricity when the current exceeds a safe level. This prevents overheating and potential damage to the wiring and connected components.

Circuit breakers serve as vital safety devices. When an excessive current flows through the circuit, indicating an overload situation, the circuit breaker trips, opening the circuit and stopping the current flow. This feature is essential in maintaining the integrity of the electrical system and ensuring safe operation. Unlike fuses, which must be replaced after they blow, circuit breakers can be reset after tripping, making them convenient for repeated use.

In contrast, fuses also provide overcurrent protection, but they operate differently by melting when excess current flows, requiring replacement. Wire connectors do not provide overcurrent protection; they are simply used to connect wiring. Relays are used to control circuits by opening and closing contacts but do not directly protect against excessive current.

Thus, the circuit breaker plays a crucial role in safeguarding the instrument lighting system by managing current flow effectively, making it the correct answer for this question.