What are oil filled capacitors primarily used for?

Oil-filled capacitors are primarily used as running capacitors in motor applications due to their ability to handle high voltage and manage extensive electrical loads effectively. These capacitors are insulated with oil, which not only enhances their dielectric strength but also provides cooling and extends their operational life in demanding scenarios. In motor circuits, running capacitors help improve the starting torque and efficiency of the motors, allowing them to operate smoothly and effectively.

While there are other applications for capacitors, the specific features of oil-filled capacitors, such as their durability in fluctuating loads and high voltage environments, make them particularly suitable for use as running capacitors in motors. This application leverages their ability to maintain performance under constant electrical stresses associated with motor operation.