What typically causes capacitor failure in electrical systems?

The correct answer is dielectric shorting. This phenomenon occurs when the insulating material between the capacitor plates, known as the dielectric, becomes compromised. If the dielectric material degrades or breaks down, it can result in an unintended electrical connection between the plates, leading to a short circuit. This sort of failure is critical because it can cause the capacitor to lose its ability to store charge and can also lead to overheating, swelling, or even bursting if the capacitor is subjected to the conditions that follow from the shorting.

While overheating, excessive voltage, and incorrect installation are all factors that can adversely affect capacitors, they do not directly describe the shorting behavior of the dielectric material. Overheating may be a result of excessive current or voltage, and incorrect installation can lead to poor electrical connections, but these issues relate more to operational failures than the specific failure mode of the dielectric itself. Hence, dielectric shorting is the most precise answer to the cause of capacitor failure in electrical systems.