Voltage transformer secondary loop end fuse selection principle - Database & Sql Blog Articles

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(1) At the exit of the secondary circuit of the voltage transformer, a total fuse or automatic switch shall be installed to cut off the short circuit fault of the secondary circuit.

(2) If the secondary circuit of the voltage transformer fails, the delay of the secondary circuit failure may cause the protection device and the automatic device to malfunction or refuse. Therefore, a device with a good monitoring voltage circuit should be installed. In this case, an automatic switch should be used as the short-circuit protection, and the auxiliary contact should be used to send a signal.

(3) During normal operation, there is no voltage across the triangular auxiliary winding of the secondary open of the voltage transformer, and it is impossible to monitor whether the fuse is disconnected; and if the fuse is blown, if the system is grounded, the protection will refuse to operate, so the open triangular winding exit is not A fuse should be installed.

(4) The secondary voltage branch circuit of the voltage transformer connected to the meter and transmitter should be equipped with a fuse.

(5) The voltage transformer neutral point lead-out line is generally not equipped with a fuse or an automatic switch. When phase B is grounded, its fuse or automatic switch shall be installed between the secondary winding terminal of phase B of the voltage transformer and ground.