The disposition and connection of ZnO arresters in GIS of 110-220kV urban networks are studied. The results show that the arresters at overhead line entrances should be in-stalled at the frontier and connected in "V" mode. The synthetic housing ZnO arrester is recom-mended to be hung at the terminal pole. The relations between incoming surge overvoltage level and cable length are affected by the rated voltage
network configuration
line connection and pa-rameters. Therefore
the disposition of arresters at cable end and GIS busbar are determined by contrete computation and argumentation.