Quality metallized film capacitor properties

The quality metallized film capacitor is what the manufacturer wants to produce, and the electrical industry wants to have it. The dielectric strength is the large peak voltage that the capacitor can withstand at the rated room temperature. It can be measured by applying a voltage of a specified multiple of the rated voltage value through a current limiting resistor of 100 Ω per volt for one minute.

The quality of the quality metallized film capacitor is applied to the capacitor at a rated temperature for a specified multiple of voltage for 500 or 1,000 hours. The appearance is not damaged and the capacitance value does not change by more than plus or minus five percent. The insulation resistance does not drop to the initial value. At 50% limit, the loss tangent will not exceed the initial limit.

Metallized film capacitors differ from foil structures in that they are sprayed onto a dielectric film by thin film vacuum deposition to form a capacitor plate that is smaller in size and lighter in weight than capacitors made from separate foils and layers. The unit Farah has lower cost and self-healing. Although its current capacity is relatively low, it is small in size and low in cost, and is attractive at high rated capacity.

Self-healing is also required for quality metallized film capacitors. In the case of problems with metallized film capacitors or clicks, the metallization coating at the breakdown point or problem location will be volatilized instantaneously under the action of the arc. The two poles of the capacitor are again short-circuited to resume normal operation.