DIN 53481 Testing of Electrical Insulation Materials - Determination of Electrical Breakdown Voltage and Electrical Power

Under normal conditions, dielectric (insulating) materials do not allow electric current to pass through them, even if there is a potential (voltage) between them. However, all materials will eventually conduct current if the applied potential is high enough. The process during which this occurs is called dielectric breakdown (insulation failure). The value of the electric potential at which this occurs is also called the breakdown voltage.

The dielectric strength is important because the breakdown voltage becomes larger for thicker materials and smaller for thinner materials, but the dielectric strength remains theoretically unchanged. Therefore, dielectric strength is considered more of a material property and breakdown voltage more of a system property.

The breakdown voltage of an insulator is the minimum voltage that causes a portion of the insulator to experience electrical breakdown and become electrically conductive. In the DIN 53481 standard published by the German Standardization Institute (DIN), a test method is defined for the determination of electrical breakdown voltage and electrical power in relation to electrical insulating materials. Materials are generally grouped as conductors or insulators according to their resistivity. A conductor is a substance that moves freely in the material and contains charged particles. Insulators are materials that resist the flow of a current.

Dielectric strength is measured as the maximum voltage required to cause dielectric breakdown in a material. It is expressed in Volts per unit thickness. For a plastic material, dielectric strength ranges from 1-1000 mV/m. Higher dielectric strength corresponds to better insulation properties. Breakdown voltage is the threshold voltage at which breakdown occurs.

The standards used to measure the dielectric strength of a material are:

• ASTM D149-20 Standard test method for dielectric breakdown voltage and dielectric strength of solid electrical insulating materials at commercial power frequencies
• IEC 60243-1 Electrical resistance of insulating materials - Test methods - Part 1: Tests at power frequencies

Among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors, our organization also provides test services for the determination of electrical breakdown voltage and electrical power in electrical insulation materials, within the scope of DIN 53481 standard, with its trained and expert staff and advanced technological equipment.