Due to the strong arc extinguishing ability of vacuum switches, they can cause special operating overvoltage during disconnection, resulting in insulation breakdown of high-voltage motors, circuit transformer faults, and even damage and burning of the switchgear itself. The TBP three-phase combined overvoltage protector (hereinafter referred to as the protector) is a product specifically designed for 3~35kV medium voltage systems to protect electrical equipment from internal operating overvoltage (mainly vacuum switch forced cut-off overvoltage, also including multiple reignition overvoltage and overvoltage generated by asynchronous three-phase disconnection). The core working principle is to use a discharge gap to divide the voltage of the zinc oxide valve plate, reduce the residual voltage of the product's operation impact protection, and achieve protection against overvoltage during operation; At the same time, the four-star connection method (commonly known as the trident connection method) is used to set a common neutral point, achieving rapid response to phase to phase overvoltage and effectively preventing phase to phase insulation breakdown of three-phase loads. Used to protect pressure gauges, pressure transmitters, and other pressure measuring instruments. When the pressure suddenly rises during process production, ensure that the pressure borne by the pressure gauge does not exceed the maximum value indicated by the pressure gauge range