Surge Arrester is the basis of insulation co-ordination for power equipment. It is used for limiting over voltage. There are two types of MOA, with gaps or gapless, according to their structures and types of materials of housing (porcelain housing and silicone rubber/polymeric housing). The product series are Y5W, Y10W, HY5W, HY10W, with voltage rating 3~36kV. MOAs have many advantages, such as fast response, good steep wave characteristic, low residual voltage, large capacity of rectangular wave, simple structure and light weight, good anti-pollution ability, easily maintenance.

Medium voltage polymeric surge Arrester has an advanced envelope system for the ZnO varistor stack. This new system improves resistance to weather conditions (no moisture ingression) and mechanical characteristics. Such structure offers high cantilever and torsion strength. Covered with polymeric (silicone rubber) housing over this envelope, such housing is highly resistant to UV radiation, polluted and all weather conditions. Such surge Arrester is specially recommended for high polluted areas. Disconnector can supplier with surge Arrester, which is coordinated with the over current protection of the distribution lines.

Surge Arrester consists of 5KA type which are used on network with a moderate lightning exposure, and 10KA type which are used on network with a strong lightning exposure. Applicable to environment of ambient temperature range of +40 to -40 centigrade, power frequency range of 48~62 Hz, utmost wind velocity no higher than 35m/s.

Distribution surge Arrester meets IEC 60099-4 standard.