Film capacitors 2018

What factors affect the failure rate of a film capacitor?

In the case of film capacitors, the two most relevant parameters affecting the failure rate are tem-perature and voltage. In the IEC61709:2011 standard, models for stress factors are consequently applied in order to convert the failure rates under reference conditions to values applying for oper-ating conditions.

How reliable are film capacitors?

The most important reliability feature of film capacitors is their self-healing capability, i.e. their abil-ity to clear faults (such as pores or impurities in the film) under the influence of a voltage. The metal coatings, vacuum-deposited directly onto the plastic film, are only 20 50 nm thick.

How is the finish of film capacitors assessed?

The finish of film capacitors is assessed in compliance with EPCOS finish specifications. For more detailed specification, refer to the "General technical information" chapter. When applicable, the individual data sheets are definitive for finishing. The failure rate is defined as the failure percentage divided by a specified operating period.

Can a film capacitor withstand vibration?

A capacitor's ability to withstand vibration (e.g. as occurs in applications involving rotating machin-ery), is tested to IEC60068-2-6:2007. EPCOS offers film capacitors especially designed for operation under more severe vibration regimes, such as those found in automotive applications. Further information available upon re-quest.

Are the dimensional drawings definitive for the finish of film capacitors?

The dimensional drawings in the individual data sheets are definitive for the dimensions. The finish of film capacitors is assessed in compliance with EPCOS finish specifications. For more detailed specification, refer to the "General technical information" chapter. When applicable, the individual data sheets are definitive for finishing.

What is a metallized capacitor?

An M ( metallization) is prefixed to the short identification code of capacitors with metallized films. *) MFP and MFT capacitors are constructed using a combination of metal foils and metallized plastic films. They are not covered by DIN EN 60062:2005. The following table is a summary of important technical data.