Summary of Current Transformer Performance Functions

(1) The secondary side of the current transformer must not open the circuit during operation. After the secondary side is opened, the insulation breakdown is caused due to excessive iron loss, or the voltage of the secondary winding increases, resulting in the danger of high-voltage electric shock. Therefore, when replacing the ammeter, active power meter, reactive power meter and other instruments, the current loop should be short-circuited before replacing the measuring instrument. When adjusting the meter, connect it to the secondary circuit, then remove the short wire and check if the meter is normal.

If sparks are found when the stub is removed, the current transformer is open and should be re-shorted immediately so that there is no open circuit in the meter circuit before the stub is re-disconnected. When removing the current transformer for short-circuit work, it should be placed on an insulating pad. In addition, the protective device of the current transformer circuit should be disabled. After the work is completed, the protection device can be put into operation.

(2) If the current transformer has a buzzing sound, check whether the inner core is loose and tighten the core bolts.

(3) At one end of the secondary side of the current transformer, the tank shell must be reliably grounded.

(4) When the insulation resistance of the secondary coil of the current transformer is less than 10_(20) megohm, it must be dried to restore the insulation before use.