To prolong the life of electrical systems and motors, regular insulation resistance testing is required. Over the years, after many cycles of operation, electric motors are exposed to environmental factors such as dirt, grease, temperature, stress, and vibration. These conditions can lead to insulation failure, resulting in loss of production or even fires.
An effective motor insulation resistance system has high resistance, usually (at an absolute minimum) greater than a few mega ohms (MΩ). A poor insulation system has lower insulation resistance. The optimal insulation resistance for an electric motor is often determined by the manufacturer’s specifications, the criticality of the application where the motor is used, and the environment where it is located.
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