CWEA Maintenance Technologist Practice Test

What mechanism is typically employed to protect equipment from overload?

1. Circuit breaker

2. Fuse

3. Thermostat

4. Contactor

The correct answer is: Circuit breaker

The mechanism typically employed to protect equipment from overload is a circuit breaker. Circuit breakers are designed to interrupt the flow of electricity in a circuit when an overload condition is detected, thereby preventing damage to the equipment and reducing the risk of fire hazards. They act as automatic switches that will trip under excessive current conditions, effectively isolating the circuit and protecting both the devices connected to it and the overall electrical system. In contrast, while a fuse also serves to protect against overloads, it does so in a different manner. Fuses are designed to melt and break the circuit when excessive current flows through them. However, once a fuse has operated, it must be replaced, making circuit breakers generally more convenient for ongoing protection and resettable functionality. Thermostats and contactors serve very different roles within an electrical system. Thermostats are primarily used for temperature regulation, and while they can play a part in protecting equipment by controlling heating systems, they do not specifically protect against electrical overloads. Contactors are used to control the flow of electricity in high-power applications, serving as an electrical switch rather than a protective device against overloads.