What is the purpose of the service factor indicated on a motor's nameplate?

The service factor indicated on a motor's nameplate serves to represent additional operational capacity. It provides a measure of the motor's ability to handle loads beyond its rated capacity without overheating or sustaining damage. For example, if a motor has a service factor of 1.5, it implies that the motor can safely operate at 150% of its rated horsepower for short periods without compromising its performance or reliability. This is vital for applications where peak demands might occasionally exceed normal operating conditions, allowing for flexibility in operational tasks while ensuring the longevity of the motor.

The other options, while related to motor specifications and performance in various ways, do not capture the essence of what the service factor represents. The design voltage levels pertain to the electrical specifications, the warranty period is related to coverage provided by the manufacturer, and installation requirements are usually determined by other aspects of motor design and intended usage, but they do not reflect the capacity for short-term overloads that the service factor indicates.