避雷器是设备。
Arresters are devices.
能释放雷电或兼能释放电力系统操作过电压能量，保护电工设备免受瞬时过电压危害，又能截断续流，不致引起系统接地短路的电器装置。
It can release thunder and lightning or simultaneously release the power system operating overvoltage energy, protect electrical equipment from instantaneous overvoltage hazards, and cut off the intermittent current, so as not to cause grounding short circuit of the system.
避雷器通常接于带电导线与地之间，与被保护设备并联。当过电压值达到规定的动作电压时，避雷器立即动作，流过电荷，限制过电压幅值，保护设备绝缘；电压值正常后，避雷器又迅速恢复原状，以保证系统正常供电。
The lightning arrester is usually connected between the live wire and the ground in parallel with the protected equipment. When the overvoltage reaches the specified operating voltage, the arrester acts immediately, flows through the charge, limits the amplitude of the overvoltage, and protects the insulation of the equipment. When the voltage value is normal, the arrester quickly restores to its original state to ensure the normal power supply of the system.