Lightning current and overvoltage withstand capacity test of low voltage systems facility wiring

The insulation of equipment and electrical wiring will withstand the overvoltage wave for as long as it past, and the conductor of equipment and electrical wiring will be also subjected to the current wave for as long as it traveled. It is very necessary to know the voltage and current withstand characteristics of electrical wiring and component for lightning protection design and insulation cooperation. Withstand capacity test under lightning current, lightning impulse voltage, 50 Hz AC voltage and DC voltage of many kinds of low voltage systems facility wiring have been conducted in laboratory. The result shows that the breakdown and damage of conductor and insulation layer are mainly caused by common effect of thermal effect, electromotion force effect and electric field. Different conductors or products will take different phenomena under different current or voltages, so it is very necessary to conduct withstand capacity test for on site use. Under the same connection and arrangement, the DC breakdown voltage is the highest and the impulse breakdown voltage and AC breakdown voltage are lower.