1. Zero-sequence current transformer is to test the zero-sequence current.

2. Zero sequence current refers to the vector sum of three-phase currents. Under normal conditions, the sum is zero.

3. When the zero-sequence current is relatively large, it means that there is a fault in the system. Use this to maintain the trip. Zero-sequence maintenance is often used in outlet cabinets of 10 kV and above. A zero-sequence transformer must be installed.

1. According to the definition, it is known that it is the sum of three phases. Therefore, there is a through-core transformer at the bottom of the cabinet. (The three-phase outlet cable goes through).

2, the secondary outlet of the zero-sequence transformer is connected to maintenance installation, or current relay. After maintenance installation or relay, trip switch. Play a maintenance role.

　　 Remarks: The integral transformer device should be carried out in the cable laying line, and the cable should pass through the transformer when laying.