Current transformer wiring inspection method

1. In order to check whether there is disconnection and short circuit on the secondary side, disconnect the wires connected to the A-phase voltage terminal and c-phase voltage terminal of the electric energy meter successively. Under normal circumstances, the disc of the electric energy meter should rotate.

If the electric energy meter disc does not rotate after cutting off the phase a voltage, it indicates that the phase C of the current transformer is disconnected or short circuited. On the contrary, if the electric energy meter disc does not rotate after cutting off the phase C voltage, it indicates that the phase a of the current transformer has been disconnected or short circuited.

2. How to determine whether the voltage transformer is connected reversely? We can distinguish by connecting the galvanometer to the secondary side of the current transformer successively and detecting the current. In case of star connection, the current of middle phase is twice that of other phases.

3. One ammeter can be used to detect whether the current transformer is well grounded. In the process of detection, one side of the ammeter needs to be connected with the terminal block of the voltage transformer that is not connected to the grounding device, and the other end is connected to the secondary line of the current transformer. If there is a grounding device, the current of the ammeter is expressed as 100V, if not, the current is 0.

4. If you want to verify whether the grounding device is appropriate, you can also use current for verification. The method is to connect one 1 terminal of the ammeter to the grounding device and the wire of the other terminal to the ammeter. If the terminal is properly connected, the ammeter has no indication.