The temperature rise of a motor is due to the difference between the
absorbed power and the output power of the motor. This difference is
the power loss.
Temperature rise is also related to the fact that power loss, in the form
of heat from the motor, is not rapidly absorbed by the ambient air
(thermal resistance). The thermal resistance of the motor can be greatly
reduced by ventilation.
The nominal operating characteristics correspond to the voltagetorque-
speed characteristics required for continuous operation at
an ambient temperature of 20˚ C. Only intermittent duty is possible
outside these operating conditions : without exception, all checks
concerning extreme operating conditions must be performed in
the actual customer application conditions in order to ensure safe