What type of overload protection is commonly used in circuits with induction motors?

Thermal overload relays are particularly suited for protecting induction motors from conditions such as overloads. When an induction motor experiences an overload, it draws more current than its rated capacity. This excess current generates heat, which can lead to damage of the motor windings and other components.

The thermal overload relay operates by utilizing a bi-metallic strip or other temperature-sensitive mechanism that responds to the heat produced by the increased current. As the temperature rises, the bi-metallic strip bends and eventually trips the relay when it reaches a certain threshold, thereby interrupting the current flow to the motor and preventing overheating.

This type of overload protection is favored in induction motors because it provides a straightforward and effective means of preventing thermal damage under overload conditions, thereby ensuring the longevity and reliability of the motor.