Abstract: A system and method that provides early warning of a capacitor failure before it causes a functional failure by including a plurality of redundant capacitive elements arranged in parallel in a capacitor module. A monitor measures a value corresponding to the total capacitance of the module under a selected system operating condition to obtain a baseline value. During system operation, the monitor compares a measured value with the baseline. If any of the capacitive elements in the module fails in an open state or a shorted state, the measured value will differ respect to the baseline, but the remaining capacitive elements allow the system to continue to operate. The user can therefore replace the failed capacitor as part of scheduled maintenance, reducing maintenance and operating costs caused by unexpected, unscheduled maintenance.

Abstract: An electric device includes an electric element, such as a wound film capacitor, with power input and output leads. The electric element includes a coating layer of parylene that provides moisture resistance and low gas and moisture permeability to protect the electric element from short and long term moisture degradation effects. A known case layer is located adjacent to the coating layer. The case layer is a metal, epoxy-based, silicone-based, or polymer material that encapsulates the coating layer and the electric element to protect the coating layer and electric element from physical damage.