Failure mode tests for distribution type metal-oxide surge arresters with polymeric housing

The paper records the results of an extensive investigation conducted in Italy regarding the setting up of testing procedures for the assessment of the failure mode behaviour of polymeric housed distribution type surge arresters. Different sample preparation methods and short circuit test procedures are compared and discussed. The evaluation of the performance takes into consideration all the major hazard issues, such as the ejection of fragments, the detachment of the connections and fire ignition. Several aspects to be taken into account for the standardization of the failure mode test are also addressed