A circuit breaker timer is a device or control function that automatically operates a circuit breaker after a preset time delay. It is used to protect electrical equipment from faults such as overloads, short circuits, or abnormal conditions. When a fault occurs, the timer allows the breaker to remain closed for a specified period before tripping. This helps prevent unnecessary interruptions and provides coordination between protective devices. Circuit breaker timers are commonly used in power systems, industrial electrical installations, and testing equipment to ensure safe and reliable operation.