Why should the secondary winding of current transformer and voltage transformer be grounded in use?

The secondary winding of the current transformer and the voltage transformer should be grounded during use, to prevent the high voltage from being connected to the low voltage through the transformer after the transformer insulation is broken down, which will hurt the instrument and the user, and the secondary winding of the transformer will be damaged. Grounding the next point will not affect the normal use of the equipment, but also ensure the safety of personnel and equipment. In order to ensure safety, the secondary side of the current transformer must be grounded, and it plays a protective role when the secondary side of the current transformer is in danger of high voltage to ensure the safety of people and equipment. The current transformer is used in the production process to monitor the use of each primary equipment in the system to ensure the safe use of the power system. The current transformer usually converts the large current of the primary circuit into a small secondary current proportional to it, and finally outputs the small current on the secondary side to the secondary instrument, relay protection, and automatic device for use.

Therefore, the current transformer is an AC current source for electrical control, regulation, measurement and protection components, and is also a hub for the connection between the electrical secondary circuit and the primary circuit. Why can't the secondary side of the current transformer be opened? Because the secondary circuit of the current transformer is open, the secondary current disappears, and the demagnetization effect also disappears, which will cause a high magnetic density in the iron core. And because the number of turns of the secondary side winding is much larger than the number of turns of the primary side winding, once the secondary side is open, a very high voltage will also appear, sometimes as high as thousands of volts, so it not only endangers the secondary side equipment, but also seriously affects the human body. Safety.