Motor Running Hot
 

Heat is the enemy of electric motors.  For every ten degrees a motor runs above its rated temperature, the motor life will be cut in half.  Excessive heat will cause premature failures.  

Today’s “T” frame motors run hot.  It is the way they are designed.  The question should be “is the motor running over temperature”.  If the motor is running over temperature what are the possible causes? 

§ Overload.  Check the amperage.  If the amperage is higher than the nameplate rating the motor may be overloading.  In some cases, such as compressors, the motors are very often running in the service factor.  Check the service factor amps in this case.
§  Ventilation. Is the airflow restricted to the motor?  If the air intake is blocked or the air passages over the motor are blocked the motor will overheat
§ The motor horsepower rating is too low
§ Unbalanced voltage
§ Load cycling
§  Excessive ambient.
§  Mechanical stresses.

Heat is not always a problem, however overheating is a serious problem that will burn the motor winding and affect the motor mechanically .  The reason for the overheating must be identified and rectified if the motor is to continue in production.