Has direct bearing on the life of a given motor and when considering life expectancy, the following application considerations that affect the motor's operating temperature, should be taken into account

1. Bearing

2. Lubricants

3. Duty Cycle

4. Radial Loading

5. Axial Loading

6. Mounting

7. Enclosure

8. Ambient Temperature

9. Ventilation

As a general rule of thumb each 10fC increase in total temperature over the maximum permissible to the motor insulation system halves its life. Bearing or gear lubricant life is halved for every 25fF (approx. 14fC) increase in temperature. Heat eventually causes deterioration of most lubricants and seals leading to leakage and increased friction.