Most NEMA-rated general purpose motors have an overcurrent trip class rating of?

Most NEMA-rated general purpose motors are designed with an overcurrent trip class rating of Class 20. This classification is essential because it specifies the thermal overload protection needed for these motors during operation. Class 20 overload relays are intended to provide adequate protection while allowing for the inrush current that occurs when motors start, which can be several times higher than the normal running current.

The Class 20 rating allows for a delay in tripping under starting conditions, ensuring that the motor can start without interruption. Moreover, this rating is aligned with the typical thermal characteristics of general purpose motors, enabling them to withstand normal operating conditions without tripping under brief overloads. This is crucial for maintaining productivity in various industrial and commercial applications where these motors are used.

The other classes, while relevant to different types of motors or applications, do not match the standard expectations for general purpose motors as defined by NEMA guidelines.