How to check the secondary open circuit fault of current transformer?

1) The indication of loop instrument decreases abnormally or is zero. For example, the current circuit used to measure the meter is open; The indication of three-phase ammeter will be inconsistent and the indication of power meter will be reduced; The meter does not turn or the number of revolutions slows down; If there is sometimes no indication in the table; It may be in a semi open circuit state;

2) Whether the CT body has noise, uneven vibration, serious heating, smoking and other phenomena; Of course, these phenomena are not obvious when the load is small;

3) CT secondary circuit terminals and component wire ends have discharge and ignition;

4) Malfunction or refusal of relay protection; This kind of situation can be found and handled in case of false tripping or skip tripping;

5) The watt hour meter, relay, etc. smoke and burn out. While the reactive power meter and watt hour meter, the transmitter of the telecontrol device and the relay of the protection device are burnt out; It will not only open the CT secondary circuit; It will also make Pt short circuited for a second time.