| | | DC FILTERING The series uses a dry-wound (non-oil-filled) segmented metallized polypropylene or polyester dielectric, which features the controlled self-healing process, specially treated to have a very high dielectric strength in operating conditions up to 85°C, and up to 105°C for the FFB series. For more information on how segmented metallized films and controlled self-healing works see a complete presentation. AN ALTERNATIVE TO ELECTROLYTICS FF series capacitors can be a very interesting alternative to electrolytic capacitors, because they can withstand much higher levels of surge voltage, very high rms currents and offer longer lifetimes (see section on lifetime as well as determination tables and application notes). APPLICATIONS The FF series capacitors are specifically designed for DC filtering and low reactive power. Main applications are: power supplies manufacturer, motors, drives, electric utilities, induction heating, people movers, tramways, metro systems, unit supported power supplies, etc. STANDARDS | | LIFETIME EXPECTANCY One unique feature of the segmented metallized technology is how the capacitor acts at the end of its lifetime. While electrolytic capacitors present a strong risk of short-circuit and consequently explosion, this film capacitor simply experiences a loss of capacitance of about 2%, with no risk of explosion. The capacitor gradually loses capacitance over its lifetime (like a battery), and eventually becomes an open circuit. Lifetime, therefore, as it is defined here, is a function of several elements: • Decrease in capacitance limit (-2% in the example above) • Average applied voltage (expressed as a ratio vs nominal rated voltage) • Average hot spot temperature By changing any of these parameters we can change the defined "lifetime" of the capacitor. This lifetime is theoretical, however as the capacitor continues to function even beyond the preestablished limit on capacitance decrease. See lifetime expectancy tables as part of this catalog to help in this determination. | | |
| | | IEC 61071-1, IEC 61071-2: IEC 60068-1: IEC 60077: UL 94: NF F 16-101: NF F 16-102: IEC 60384-2: IEC 61881: | | Power electronic capacitors Environmental testing Rules for electric traction equipment Fire requirements Fire and smoke requirements Fire and smoke requirements Fixed metallized polyester capacitors Railway applications, rolling stock equipment, capacitors for power electronics | | |