An Aluminum Electrolytic Capacitor has a polarity. In operation this polarity needs to be considered and adhered.
Reverse voltage can damage or destroy an Aluminum Electrolytic Capacitor. This can finally lead to a malfunction.
If the polarity in a circuit will be switched or possibly can be reversed, the usage of a non-polar capacitor shall be applied.
The polarity of an Aluminum Electrolytic Capacitor is for THT radial types marked like following.
The terminal with shorter lead wire marks the negative terminal. On the sleeve the negative terminal is marked with a color band and thereon
are minus signs given. For further details see technical drawing on A1 dimensions in this datasheet.
Avoid any overvoltage and do not apply a continuous overvoltage. If an overvoltage is applied to the capacitor, the leakage current can increa-
se drastically. The applied working voltage is not allowed to exceed the rated working voltage of the specific capacitor.
1.3 Operating Temperature
The capacitor shall not be operated above the operating temperature, which is stated within this datasheet of the specific capacitor. The
achievable lifetime of the capacitor is correlating to the applied temperature. In order to achieve the maximum lifetime, the capacitor should be
operated by the lowest possible temperature conditions within the application.
1.4 Ripple Current
The applied ripple current shall not exceed the specified maximum ripple current of the capacitor.
If a higher ripple current is applied as permitted, it can cause excessive heat generation and higher temperature inside the capacitor. This
happens due to pole change effects, if ripple current is applied to the capacitor. This can result in damage or lifetime shortage of the capacitor
and may cause deterioration.
Electrolytic capacitors are regularly not designed for usage in AC applications and ripple current is applied / based due to parasitic effects on
Please see electrical specification within this datasheet for maximum allowed ripple current.
1.5 Charge and Discharge
Frequent and quick charge / discharge cycles may generate heat inside the capacitor. In worst case this can cause a decrease of capacitance,
an increase of leakage current or breakdown.
Applications with rapid charge and discharge cycles should be avoided. For assistance with your application please consult our technical sup-
On most Aluminum Electrolytic Types types, a predetermined breaking point is given on the top of the component, which is the so called vent.
The vent is there to assure a possible pressure relief and to avoid that the capacitor can explode due to internal pressure, which can occur by
applying reverse voltage or a too high ripple current.
A space of at least 3mm above the vent is recommended, in order to assure the full function of the vent. If less space is present the vent may-
be cannot operate correctly / completely.
The sleeve material consists of PVC (polyvinyl-chloride). If excessive heat is applied to the sleeve (e.g. soldering process, etc.) the sleeve may
crack or deform.
If the capacitor will be exposed to xylene, toluene or likewise and will be afterwards heated, the sleeve may crack or deform.
The sleeve does not assure any electrical insulation. It is to avoid to use / place the product on a spot where electrical insulation is needed. To
assure electrical insulation, especially to the case of capacitor, further actions need to be taken.
1.8 Storage Conditions
The storage conditions for a capacitor are recommended to be 5 °C up to 35 °C and less than 75 % rel. humidity.
Do not expose the capacitor to environments with hazardous gas, ozone, ultraviolet rays or any kind of radiation. Avoid any contact of the ca-
pacitor with direct sunshine, saltwater, spray of water or types of oil during storage..
If a capacitor is stored for a long time without applying voltage or storage conditions of 35 °C or above and more than 75 % relative humidity,
the leakage current may increase.
The leakage current will return to normal level when applying the rated voltage to the capacitor before use. If the capacitor was stored for mo-
re than 6 months, it is recommended to apply DC working voltage to the capacitor for 30 minutes through a 1 kΩ protective series resistor.
All products shall be used before the end of the period of 12 months based on the product date code, if not a 100 % solderability cannot be
guaranteed. The capacitance tolerance as specified within the datasheet is only valid on the date of delivery.
1.9 Wave Soldering
The detailed soldering instruction is given within Soldering Specification in this datasheet.
During wave soldering only the pins / terminals should have contact with hot solder bath / wave. Assure that no direct contact of capacitor bo-
dy with hot solder bath / wave or any other component will happen. Soldering must be done from the opposite PCB side where capacitor body
I Cautions and Warnings:
The following conditions apply to all goods within the product series of WCAP-ATUL
of Würth Elektronik eiSos GmbH & Co. KG:
This electronic component has been designed and developed for usage in general electronic equipment only. This product is not authorized for use in equipment where a higher safety standard and reliability standard is especially required or where a failure of the product is reasonably expected to cause severe personal injury or death, unless the parties have executed an agreement specifically governing such use.
Moreover Würth Elektronik eiSos GmbH & Co KG products are neither designed nor intended for use in areas such as military, aerospace, aviation, nuclear control, submarine, transportation (automotive control, train control, ship control), transportation signal, disaster prevention, medical, public information network etc.. Würth Elektronik eiSos GmbH & Co KG must be informed about the intent of such usage before
the design-in stage. In addition, sufficient reliability evaluation checks for safety must be performed on every electronic component which is used in electrical circuits that require high safety and reliability functions or performance.