Precautions for using current transformers

1. For the wiring of current transformers, we should all follow the principle of series connection, that is, the primary winding should be connected in series with the test circuit and the secondary winding should be connected in series with all instrument loads.
2. Choose the appropriate change according to the magnitude of the measured current, otherwise the error will increase and increase. At the same time, one end of the secondary side must be grounded, so as not to prevent high voltage from entering the primary side once the insulation is damaged, and the second low voltage The side will cause the danger of the life of the staff and the irreversible accident of the equipment.
3. The secondary side is absolutely not allowed to be open circuited. Once the circuit is open, the measured current will all become magnetizing current and increase, resulting in over-saturation of the iron core and serious heating due to magnetization. If it is even more serious, the coil will be burned and the magnetic circuit will be over-saturated and magnetized. After that, the error increases. When the current transformer is working normally, the secondary side is more like a short circuit. If it is suddenly opened, the electromotive force will suddenly change from a small value to a large value, and its value can reach thousands or even tens of thousands. The current of 1 volt will seriously endanger the safety of the staff and the insulation performance of the instrument. In the process of using, if any of the above problems occur, the load of the circuit should be removed immediately, and then it can be used again after the parking treatment and other treatment are complete.