Overload protection for a motor starter is chosen based on what parameter?

Overload protection for a motor starter is primarily based on motor amperage, which is crucial for ensuring that the motor operates within its safe limits. The motor's amperage directly correlates with the load it is designed to handle; if the amperage exceeds the specified threshold, it can lead to overheating and potential damage to the motor windings or insulation.

Choosing the overload protection based on motor amperage allows for effective monitoring of the electrical current that the motor draws during operation. In the event of an overload condition—like when the motor encounters greater resistance than anticipated—the overload protection will engage, interrupting the power supply to the motor to prevent damage.

While motor size is related to its amperage, it does not provide the specific current characteristics necessary for overload settings. Voltage ratings and electrical resistance also play roles in the overall functioning of electrical systems but are not the primary factors in selecting overload protection, which centers around the motor’s amperage to ensure appropriate safety and performance during operation.