The insulation class of a motor is a letter rating that
indicates the amount of temperature rise the insulation of wire can withstand.
The numbers in the insulation class are listed in degrees Celsius (°C).
The table in Fig. 1 shows typical insulation classes for motors. The
insulation class and other temperature-related features of a motor will
help determine the temperature rise the motor can withstand.
Above: Fig. 1: Insulation class for motors. This table indicates the
amount of temperature for which the wire’s insulation is rated.