Polymeric Metal-Oxxide Surge Arrester: 1.Metal-oxide surge arrester provides the most advanced protection against over-voltage in the world,since MOA' resistors are made up of zinc oxide films 2.MOA has a good voltage-ampere characteristics as compared with silicone carbide arrester,its volt/ampere characteristic is much superior and results in much better performance 3.A micro ampere level current flows while MOA is operating under normal voltage,but the amount of the current will be thousands amperes when MOA is subjected to over-voltage,because of MOA has a good non-linear characteristics,Hence MOA provide excellent protection for the HV equipment,especially the transformer,cables and switchgear