Good examples would be oil burner motors, condenser fan motors, and double shaft fan and blower motors. The table below lists the NEMA service factors for single phase, dripproof motors. Totally enclosed and explosion proof motors have 1.0 service factors, except where noted. A manual overload must be physically reset to restart the motor. An automatic thermal overload will stop the motor when it is overloaded or overheated and restart it after the motor has cooled down.
None means the motor has no protection.
Thermostats are embedded in the winding and connected to the motor starter control circuit. Most home and farm applications require single phase motors, while most factories and large commercial and industrial users require three phase motors. Single phase motors can be used on three phase systems. Three phase motors, however, cannot be operated from single phase systems. Motor damage may result.