TNR-T series surge protection device based on YD/T 1235.2-2002 and IEC61643-1:2005 standard design and production, mainly used in communication, transportation, electric power, railway, high-rise buildings and other fields, for 40Hz-60Hz, TT, TN-C-S, TN-S, TN-C power supply system, prevent lightning voltage and operating voltage on the harm of equipment. Under normal conditions, the surge protector is in a high resistance state. When the surge or overvoltage occurs due to lightning or other reasons, the protector will rapidly lead in the nanosecond time, and the surge and overvoltage will be introduced into the earth, thus protecting the power equipment on the grid. When the overvoltage is disappearing, the protector restores the high resistance state, which does not affect the normal operation of the power grid and equipment.