Ecological design up-grade of a zinc oxide varistor suitable for distribution polymeric surge arresters

As the world is becoming more environmentally aware and European legislation is evolving with more stringent restrictions in this field. Rather than follow the emerging legislation and market requirements, AREVA T&D is anticipating this trend and adapting its products accordingly. Besides maintaining technical quality and being cost effective, the manufacture of ZnO varistors for lightning arresters must comply with environmental concerns and constraints, which are becoming more demanding and rigorous. The present communication will describe a number of taken actions to develop an environmentally friendly product the manufacturing of which has reduced or eliminated the use of materials posing health risks or contamination concerns. The new processing line does not require an acid etching step to increase the adhesion of the metal electrode to the ceramic body. A leadless glass has replaced the lead containing enamel used for passivation and at the same time the coating deposition process has been optimised. The varistor powder manufacturing process has also been redesigned to make it more efficient with less consumption of energy and material. The quantification of these environmental accomplishments during the manufacturing of ZnO varistors for distribution arresters has been evaluated using the EIME software design tool.