Which item is typically shown on an AC motor nameplate to indicate how much overload the motor can handle continuously?

Which item is typically shown on an AC motor nameplate to indicate how much overload the motor can handle continuously?

• A. HP
• B. Frame
• C. Service Factor
• D. Code Letter

Answer: (C)

The idea being tested is how a motor communicates its ability to run above its rated load. That information is shown as the service factor on the nameplate. The service factor is a multiplier that tells you how much overload the motor can handle continuously without overheating. For example, if a motor is rated at 10 HP and has a service factor of 1.15, it can deliver about 11.5 HP continuously, assuming proper cooling. This helps with selecting drives and protection because it defines the thermal headroom the motor has beyond its labeled horsepower. Other items on the nameplate serve different purposes. The horsepower rating is the normal, continuous output not the extra overload capability. The frame denotes the physical size and mounting, and the code letter relates to protection/thermal characteristics rather than how much overload can be sustained.

The idea being tested is how a motor communicates its ability to run above its rated load. That information is shown as the service factor on the nameplate. The service factor is a multiplier that tells you how much overload the motor can handle continuously without overheating. For example, if a motor is rated at 10 HP and has a service factor of 1.15, it can deliver about 11.5 HP continuously, assuming proper cooling. This helps with selecting drives and protection because it defines the thermal headroom the motor has beyond its labeled horsepower.

Other items on the nameplate serve different purposes. The horsepower rating is the normal, continuous output not the extra overload capability. The frame denotes the physical size and mounting, and the code letter relates to protection/thermal characteristics rather than how much overload can be sustained.