Which of the following statements is correct about electrical overspeed switches?

Electrical overspeed switches serve a critical safety function in elevator systems. Their purpose is to detect if the elevator car is traveling too fast, which could indicate a malfunction and pose a safety risk to passengers.

The accurate statement about the operation of electrical overspeed switches relates to their specified tripping speed. Specifically, for cars that travel at speeds between 150 to 500 feet per minute, the overspeed switch must activate before the car reaches its mechanical tripping speed, specifically at not more than 90% of that speed. This threshold is designed to ensure that the system has a reliable safety net to prevent the elevator from exceeding safe operational parameters.

By having the switch trip at this predetermined speed, it allows for a proactive safety measure that helps mitigate the risk of accidents caused by excessive speed. This regulation aligns with standard safety protocols in elevator operation to ensure passenger safety.