What happens if the secondary circuit of the current transformer in use is open?

If the secondary circuit of the current transformer in use is open, the following consequences will occur:

(1) Once the secondary circuit of the current transformer in use is open, the primary current will be used for excitation and the core flux density will increase sharply. This may not only cause the core to overheat and burn the coil, but also generate residual magnetism in the core, which deteriorates the performance of the current transformer and increases the error.

(2) Because the magnetic flux density increases sharply, the core is saturated and the magnetic flux waveform is flat, so that the secondary side of the current transformer generates a relatively high voltage, causing damage to the insulation of the primary and secondary windings, and for the human body and the instrument. Equipment poses a great threat and even damages the power system.