Design of Polymer Enclosures for High Voltage Equipment: Part I-Experiments

Throughout the industrialized world it is a legal requirement to surround outdoor as well as indoor high voltage equipment with an enclosure. Polymers are increasingly being used in the manufacture of enclosures due to their economic advantage. The induced voltage (Vi) on the surface of the enclosure must be sufficiently low so that it does not present a hazard to personnel and to animals. Vi is measured as a function of the following parameters: the dimensions of the enclosure, the distance of the enclosure from the equipment, the voltage of the equipment, the influence of environmental conditions and the placing of metal strips on the polymer surface. The induced voltage at and the short circuit current flowing through a human body upon touching a polymer enclosure are found to be at acceptably safe levels when a metallic strip network is enmeshed on the surface.