Is the increase in motor temperature caused by current?

Winding temperature rise is a key performance indicator of motor products and plays a vital role in the reliability of motors. Factors such as the motor itself, the operating environment, and load changes will all cause changes in the motor's temperature rise level. When the temperature rises, does it always show an increase in current? This is also a question worth exploring.

For the motor itself, factors such as the consistency of the electromagnetic conductor size, conductor purity, stator and rotor air gap size, structural parts heat dissipation capacity, winding core stacking coefficient, stator and rotor misalignment, etc. will all lead to higher motor losses and Motor temperature rise. Once a motor is manufactured according to established processes and combinations, its inherent temperature rise level becomes a reality. During the later use of the motor, changes in environmental conditions or load factors may cause the temperature rise of the motor to increase.

The first situation: When the motor is overloaded, whether it is intermittent or continuous, it will cause the motor current to exceed the rated current to varying degrees, causing the temperature rise to increase as the current increases. Under severe overload, the insulation performance of the motor windings deteriorates, causing the windings to completely collapse due to insulation aging in a short period of time. For most motor windings, local phase-to-phase, inter-turn or ground quality faults may occur due to quality hazards in the manufacturing process.

The second situation is that the ventilation and heat dissipation conditions are not good when the motor is running. Even if the motor current does not exceed the standard, the imbalance between heat generation and heat dissipation will lead to an increase in temperature rise. Especially for motors operating in high-altitude environments, this problem may be more serious.

The third situation is when the motor is running under severe undervoltage conditions. Even if the load does not increase, insufficient voltage will cause the current to increase when the motor is running, which is a form of relative overload, and therefore will also cause a higher temperature rise as the current increases.

Therefore, compliance with the operating conditions of the motor is crucial. For any type of motor, it is important to leave the necessary temperature rise margin.