1. The current transformer is burned because the current transformer is opened twice, which generates a high voltage, which burns the current transformer. If the current transformer is used for a long period of time, the insulation will be aging. When excessive voltage is generated, breakdown or discharge may occur locally to cause it to burn out. Once the current transformer is connected to the contact surface of the aluminum row, the oxidation is too heavy, the contact resistance is too large, the heating is burned out or the overload running time is long, which makes it burn out.
2. There are problems with the dedicated transformer user circuit breakers and wiring (generally 10kV vacuum circuit breakers and SF6 circuit breakers are equipped with overcurrent and overload protection), the circuit breaker can trip correctly when there is interphase short circuit and overload, and the overvoltage depends on the installation The zinc oxide arrester is removed. When the single-phase grounding occurs on the user side, because the circuit breaker does not trip, in order to find the grounding point, it is necessary to pull the off-line branches of a common line one by one in order to find the grounding point. The insulation of the lightning arrester on the user side cannot effectively prevent overvoltage.
3. Strengthen the user's high-voltage measurement current transformer and surge arrester high-voltage insulation test to facilitate the timely detection of the insulation aging degree of the measurement current transformer and the surge arrester, and replace it in time to avoid power failure caused by the burnout of the measurement current transformer. Regularly clean the user's equipment once to reduce pollution flashover and avoid insulation degradation