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INTERNAL CONSTRUCTION

Dielectric
MKP-/MKPg-type capacitors are based on a low-loss dielec-
tric formed by pure polypropylene film. A thin mixture of zinc winding element
and aluminium is metallized directly on one side of the PP-film
under vacuum. Our long term experience as well as on-going polypropylene film, uncoated
research and improvements in this technology ensure the ex-
cellent self-healing characteristics of the dielectric and a long
operating life of our capacitors. The plastic film is wound into polypropylene film, metal deposit on one side
contact layer
INTERNAL CONSTRUCTION by spraying with a metal contact layer, facilitating a high cur- pic.2
stable cylindrical windings on the most modern automated
equipment. The ends of the capacitor windings are contacted
rent load and ensuring a low-inductance connection between
the terminals and windings.

The link between PP-film and zinc contact layer is highly stressed during high surge or rms currents and therefore considered
very critical for operating life and reliability of the capacitor. By cutting the film for selected types in a wavelike manner, our
SINECUT™ technology increases the contact surface between film and zinc layer which substantially reduces this strain.

Impregnants
The use of impregnants and/or filling materials in capacitors is necessary in order to insulate the capacitor electrodes from
oxygen, humidity, and other environmental interference. Without such insulation, the metal coating would corrode, an increasing
number of partial discharges would occur, the capacitor would lose more and more of its capacitance, suffer increased dielectric
losses and a reduced operating life. Therefore, an elaborate vacuum-drying procedure is initiated immediately after insertion of
the capacitor elements into the aluminium case and dried insulation gas (MKPg), or biologically degradable plant oil (MKP), is
introduced. Both protect the winding from environmental influence and provide an extended life-expectancy and stable capa-
citance.

MKPg 265 – Leakage Proof and Environmentally Friendly
The gas in our MKPg-Capacitors is inert and entirely harmless to environment. When disposing of the capacitors, no liquids or
toxic gasses need to be considered. Leakage of gas is extremely unlikely if the capacitors are handled and operated properly. It
is possible to mount these capacitors in any desired position. However, should leakage occur, the leaking gas would escape into
the atmosphere causing no undesirable effects to the adjacent equipment, e.g. damage, pollution, or staining. In the long run,
such an unlikely event would result in a degradation of the capacitance; however, this process would take many months, during
which the capacitor remains functional. By using gas, we are reducing the weight of a capacitor on average by 15% compared
with resin or oil filled capacitors. This makes transportation and handling of the units easier. It also supports the concept of
mounting the capacitors in almost any position.

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