The secondary winding of current transformer and voltage transformer shall be grounded in use to prevent the high voltage from entering the low voltage through the transformer in series after the insulation of the transformer is broken down, damaging the instrument and users, and grounding the secondary one point of the transformer, which will not affect the normal use of the equipment, but also protect the safety of personnel and equipment.

In order to ensure safety, the secondary side of current transformer must be grounded, which plays a protective role when there is high voltage danger in the secondary side of current transformer to ensure the safety of people and equipment.

Function of current transformer

In the process of production, the use of primary equipment in the system is monitored to ensure the safe use of the power system. The current transformer usually transforms the large current of the primary circuit into the small secondary current which is proportional to it, and finally outputs the small secondary current to the secondary instrument, relay protection and automatic device for use. Therefore, current transformer is the AC current source of electrical control, regulation, measurement and protection elements, and it is also the junction of electrical secondary circuit and primary circuit.

Why can't the secondary side of current transformer open circuit? Because the secondary circuit of current transformer is open, the secondary current disappears, and the demagnetization effect disappears, which will cause high magnetic density in the core. And because the number of turns on the secondary side is far greater than the number of turns on the primary side, once the secondary side is open, there will also be a good high voltage, sometimes as high as thousands of volts, so it not only endangers the secondary side equipment, but also serious personal safety.