Tripolar lightning protection

The utility model discloses a tripolar lightening arrestor, which belongs to the domestic lightening arrestor technical field and comprises a shell body 1 and a bipolar metal support which is fixed in the shell body with both ends equipped with safety tubes 2. Both ends of the support are respectively connected with an output 5 and an output 8, the output 5 is arranged in the frontpiece of the shell body and is provided with two electrode pieces 4 which are respectively connected with the two poles of the metal support, the back is embedded with a short circuit board 3 which is connected with one of the poles, which forms connecting poles of the two poles on the ends of a tripolar lightening arrestor tube 9 with an outlet terminal of the other pole, thereby two electrode pieces are respectively contact-conducted with both poles on the ends of the tripolar lightening arrestor tube 9. One end of a grounding electrode of the lightening arrestor tube which is provided with two projecting symmetric ends at the center is embedded with a thermofusion piece 7 which is isolated from the other two poles, an elastic grounding piece 6 is pressed on the thermofusion piece 7, and the elasticity of the grounding piece enables the grounding piece to conduct the terminal bipolar contact short circuit of the tripolar lightening arrestor tube when the thermofusion piece is fusing. The grounding piece is fixed on the back of the shell body and is connected with a grounding wire, thereby the structure achieves the goal of no flame arc, safety, and fast discharging.