Broadening the application of the quick flashover test for RTV pre-coated glass cap-and-pin insulators sampled from service in the Italian Transmission grid

This paper broadens an investigation relevant to a novel testing procedure developed by TERNA (the Italian TSO) for RTV pre-coated glass cap-and-pin insulators sampled from high voltage overhead lines in service. Some results of the application of this procedure to a first group of RTV insulators taken from HV and EHV overhead lines after some years' service were reported in previous papers. This paper illustrates the results of the so-called Quick Flashover test performed on a second group of RTV insulators, in order to evaluate the correlation between the flashover voltages obtained with this test and the service time. The outcome is that flashover voltages from the Quick Flashover test tend to decrease as service years increase, thus such flashover voltages can serve as a prospective diagnostic quantity to assess the aging of RTV insulators on duty.