UPS Filter Capacitor Failure Analysis

Gideon Analytical Laboratories received an Areovox Z26P6045M21 45uF 600V capacitor for failure analysis. Capacitors are passive two-terminal electrical components used to store electricity in an electric field. Inside most capacitors, there are two metal plates separated by a non-conducting substance (dielectric). Filter capacitors are used for filtering undesirable frequencies and removing voltage or signal spikes in electronic circuits. They are utilized in a variety of applications. Gideon Analytical Laboratories performed failure analysis the Areovox Z26P6045M21 45uF 600V capacitor.

The Areovox Z26P6045M21 45uF 600V was electrically tested. It tested open and did not take a charge when a voltage was applied. The capacitor was also under gas pressure, which tested to be carbon dioxide. Carbon dioxide is not in the capacitor when the can is sealed shut; instead, carbon dioxide evolves as the result of the dielectric insulator breakdown. Moisture is also given off when the dielectric material carbonizes. The top portion of the filter capacitor was removed and showed a phenolic insulator used for the registration of the terminal leads. Removal also revealed a portion of the aluminum tab where the copper terminal touched the tab, and copper was blown across the top of the tab and left a trail. This phenomenon is symptomatic of a voltage spike.

Gideon Analytical Laboratories reached some The dielectric film separating the two plates had melted and carbonized in a thermal matter. The tab turned yellow because of excessive heat; it was originally cream color. The lead was surrounded by black material, which was melted insulation. This black material indicated that current is responsible for excessive heat; voltage by itself will not do this. The failure of the Areovox Z26P6045M21 45uF 600V filter capacitor was due to a voltage spike, which destroyed the dielectric film between the two aluminum foil sheets.

Trust Gideon Analytical Laboratories for all of your failure analysis needs. Gideon Analytical Laboratories has the equipment, experience, and expertise to reveal how and why electrical components fail, both in the manufacture or in the field. Information provided by failure analysis can be of invaluable importance that can help save companies time, money, and help them better prepare for the future.

Black material on lead, yellow tab

Black material on lead; yellow tab

Copper terminal touched aluminum tab

Copper terminal touched aluminum tab

Copper trail on aluminum tab

Copper trail on aluminum tab

Melted dielectric foil

Melted dielectric foil

Phenolic insulator

Phenolic insulator