Distribution lightning arrester performance data

THE intelligent application of lightning arresters requires a knowledge of their performance characteristics under conditions which are likely to be encountered in service. Data have been presented relating to the impulse characteristics of insulation both as used on lines and in transformers. In order to know what protection may be secured with certainty in service, data are also required concerning the rates of voltage rise to be expected on distribution type arresters and the current encountered as a result of natural lightning. These data are being obtained, in some measure at least, through the use of impulse current measuring devices in series with arresters in service. Very little satisfactory information is available, however, with respect to the actual rates of potential rise, in fact most of such information is based on deduction rather than actual measurement.