110kV-220kV系列额定电压9-216KV金属氧化物避雷器（以下简称MOA）是用于保护110KV电力系统的输变电设备及变压器中性点免受大气过电压和操作过电压损坏的保护电器。
      该系列MOA由主体元件和绝缘底座等组成。主体元件内部采用非线性的金属氧化物电阻片作为核心元件,它具有优异的伏安特性。当系统出现大气过电压或操作过电压时，电阻片呈现低电阻，使MOA的残压被限制在允许值以下，同时吸收过电压能量，从而对电力设备提供可靠的保护。在MOA的正常运行电压下，电阻片呈高电阻，使流过MOA的电流很小，起到与系统绝缘隔离的作用。
      复合外套OA采用优质硅橡胶为原料，从而使产品体积小、重量轻、防爆性能大大提高，硅橡胶固有的憎水性使其具有良好的耐污性能。
      瓷外套MOA带有压力释放装置，MOA故障时内部压力增大，防爆装置动作，释放内部压力。电弧从内部转移到外部，在瓷套外部形成短接，保证瓷套不炸裂。

      110kV-220kV series Rated voltage 9-216KV metal oxide surge arresters (hereinafter referred to as MOA) is used to protect the 110KV power transmission equipment and power system transformer neutral point from atmospheric over-voltage and over-voltage protection of electrical damage.
      MOA by the main elements of the series and insulated base and other components. Internal body components using nonlinear metal oxide varistor as a core component, it has excellent voltage characteristics. When the system when the atmosphere over-voltage or over-voltage operation, low resistance resistors showed that the residual pressure is limited MOA allowed value, while absorbing over-voltage energy to provide reliable protection for electrical equipment. MOA at normal operating voltage, the varistor resistance was high, the current flowing through the small MOA, the system plays the role of the insulating spacer.
      OA composite jacket made of high quality silicone rubber as a raw material, so that the products are small, light weight, explosion-proof performance greatly improved, the inherent hydrophobicity of silicone rubber it has a good stain resistance.
      Porcelain jacket MOA with a pressure relief device, the internal pressure increases when the MOA failure, explosion-proof device movement, release the internal pressure. Arc transferred from internal to external, external form in porcelain sets short, no guarantee porcelain burst.