Capacitor Storage and Use Guidelines

To ensure a safe environment and optimum performance, here are some tips for handling radial electrolytic capacitors & axial electrolytic capacitors.

OPERATING FREQUENCY: Capacitance decreases and dissipation factor increases as applied frequency increases. Be sure to check operating frequency.

STORAGE: Capacitors can be stored for long periods with little or no effect on capacitance or dissipation however leakage current increases and the capacitor's ability to withstand voltage may decrease. Any capacitors that have been stored for long periods of time should have DC voltage treatment applied.

USE OF BIPOLAR CAPACITORS: Use bipolar capacitors only in pulse circuits and polarity reversed circuits. Do not use them in pure DC or high ripple current.

POLARITY: Be sure of the polarity. If reversed voltage is applied, it may cause a short circuit or damage the capacitor. In general, you can find the polarity markings on the side of the capacitor.

DC ELECTROLYTIC CAPACITORS: DC electrolytic capacitors can not be used for AC applications.

RATED VOLTAGE: Leakage current will increase if the voltage applied exceeds the rated voltage. This in turn will damage the capacitor. The recommended voltage is 70-80% of the rated voltage.

INSULATION OF THE CAPACITOR CASE: The cathode terminal and capacitor case connect through the electrolyte. To completely insulate the case, the insulation must be at the mounting point of the capacitor.

RIPPLE CURRENT: A higher level of ripple current which is greater than the rated value may cause heating of the capacitor. This may damage the capacitor and decrease the capacitance. Ripple current should be at or below the allowable level (generally not more than 80% of the rated current).

RAPID CHARGE/DISCHARGE: In circuits where conditions include rapid charge and discharge, use specially designed capacitors to avoid damaged capacitors.

OPERATING TEMPERATURE: Capacitor characteristics are effected by by operating temperature. At higher temperatures, the leakage current increases and the dissipation factor decreases.

CAPACITOR LIFE: The life expectancy of an electrolytic capacitor is directly related to the ambient temperature. Reducing the ambient temperature by 10ºC may double the life expectancy at its rated voltage.