How to install a current transformer

- Oct 19, 2020-

1. Construct according to the drawing, the wiring is correct, the numbering mark at both ends of the wire should be clear, and the labeling range should meet the requirements of regulations.

2. Copper wires should be used for the secondary circuit wires or cables. The cross section of the current transformer loop wire should not be less than 2.5mm2, and the voltage transformer loop wire cross section should not be less than 1.5mm2.

3. The first terminal block of the current transformer outlet should be a dedicated current terminal, and the secondary winding not used by the current transformer should be short-circuited and grounded at the terminal board.

4. There should be no joints for the secondary circuit wires in the panel and cabinet, nor should there be joints in the middle of the control cables or wires. If joints are necessary, the long terminal box should be used for transition connection.

5. The polarity of the current transformer cannot be reversed, and the phase sequence and phase distinction should meet the requirements of design and regulations. For the transformer wiring for differential protection, the current phasor diagram of the two arms must be measured before putting it into operation to verify the correctness of the wiring Sex.

6. The arrangement of the wires of the secondary circuit should be neat and beautiful. The connecting screws of the wires and electrical components and terminal blocks must be free from loose connections. The distance between the wire binding points and the clamping points should meet the requirements of the regulations.

7. The secondary circuit should be well insulated to the ground, and there should be no mixed lines between the voltage circuit and the current circuit.

8. The current and voltage circuits should be grounded at one point at the secondary side outlet of the transformer.