Electrical Current Transformer wiring inspection

(1) In order to find out whether there are common faults such as disconnection and short-circuit faults on the second side of the Electrical Current Transformer, the wires connected to the phase A voltage terminal of the electric energy meter and the wire of the phase C voltage terminal can be disconnected successively. The discs should all rotate. If the disc does not rotate after the A phase voltage is cut off, it indicates that the Electrical Current Transformer phase C is disconnected or short-circuited. If the disc does not rotate after the C-phase voltage is cut off, it indicates that the Electrical Current Transformer A phase is broken or short-circuited. When the cosg value is close to 0.5 (rational), in order to prevent mis-differentiation, the phase C voltage can be used to replace the phase A voltage connected to the electric energy meter when the other of the C phase voltage is disconnected. There is no disconnection, short-circuit fault, etc. of the phase current.

(2) In order to distinguish whether the voltage transformer is reversely connected, the ammeter can be connected to the secondary side of the Electrical Current Transformer in succession, and the measured current can be used to distinguish. For the star connection, when the voltage transformer is all in one phase When the optical rotation is reversed once or again, the middle phase current will be twice that of the other phase currents. If the electrical current transformer's optical rotation is all reversed, a vector diagram of the electric energy meter coordinated wiring must be made, and then a comprehensive distinction can be made.

(3) Determine whether the Electrical Current Transformer is grounded or not, and can accurately measure with an ammeter. For accurate measurement, one side of the ammeter is connected to the ungrounded terminal of the voltage transformer, and the other end touches the re-wire of the Electrical Current Transformer. If the ammeter is marked as 100V, it indicates that the Electrical Current Transformer is grounded again. If the ammeter is marked as 0, it indicates that the Electrical Current Transformer is not grounded.

(4) Determine whether the grounding installation is right or not, and it can be accurately measured with an ammeter. Therefore, one terminal of the ammeter should be grounded. The wires of the same terminal should touch the current terminal of the electric energy meter. If the terminal is grounded, the electric current meter should be unmarked and the rotating speed of the electric energy meter's disk is not damaged. Assume the connection If the terminal is not grounded, the ammeter is marked and the rotation speed of the disk is also damaged.