The traditional ALLFILM system of conventional medium and high voltage capacitors consists of aluminium foil and polypropylene, immersed completely in synthetic, flammable oil. Breakdowns in this kind of dielectric tend to result in permanent short circuits which take out the entire capacitor element, change the voltage conditions inside the capacitor and initiate a chain reaction of further failures of capacitor elements which will end up in the loss of the entire capacitor. In three-phase capacitors, this process is usually accompanied by the occurrence of phase asymmetries which may cause damage and catastrophic failure.

The traditional ALLFILM system of conventional medium and high voltage capacitors consists of aluminium foil and polypropylene, immersed completely in synthetic, flammable oil. Breakdowns in this kind of dielectric tend to result in permanent short circuits which take out the entire capacitor element, change the voltage conditions inside the capacitor and initiate a chain reaction of further failures of capacitor elements which will end up in the loss of the entire capacitor. In three-phase capacitors, this process is usually accompanied by the occurrence of phase asymmetries which may cause damage and catastrophic failure.