Current Transformer Open Circuit Prevention Measures

It is clearly stipulated in the electrical safety work regulations that the secondary line side of the current transformer must be reliably grounded. The purpose is to prevent the high voltage of the primary side insulation from entering the secondary side and causing harm to the human body and the secondary side instrument. Therefore, the secondary line side of the current transformer must be reliably grounded.

When the secondary open circuit fault of the current transformer occurs, the correct and safe way to deal with it is: power failure on the high-voltage side, and deal with it (restore the open circuit point to the normal circuit state), but this will cause unplanned power failure;

The unconventional treatment method is: because the open circuit point of the current transformer has a discharge phenomenon when the current transformer is open, it is easier to find. A wire can be used (the diameter of the wire must meet the rated secondary current requirements of the current transformer. Generally, the rated secondary current of the current transformer is 1A or 5A, and it is completely possible to use a 2-square wire). First, connect one end of the wire to the open-circuit coil. The grounding terminal is well connected, and the other end of the wire is connected to the remote fixed connection point of the open point with an insulating tool (the insulation of the general screwdriver handle is sufficient) to achieve the purpose of shorting the open point. At this time, it is easier to It is not recommended to use this method from the perspective of safety, but in order to avoid the occurrence of assessment accidents, it can be done by experienced secondary system staff.

Prevention of current transformer secondary circuit open circuit:

(1) The secondary circuit of the current transformer is not allowed to install short-circuit protection equipment such as fuses;

(2) The secondary circuit of the current transformer is generally not switched. When it must be switched, there should be reliable measures to prevent open circuit;

(3) Current transformers are generally not used for relay protection and measuring instruments. When they must be used together, the measuring instruments should be connected through the intermediate current transformer;

(4) The terminals of the secondary windings of the installed current transformers that are not in use must be short-circuited and grounded.

(5) The terminal of the secondary circuit of the current transformer should be the test terminal

(6) It should be ensured that the connecting wires of the secondary circuit of the current transformer have sufficient mechanical strength.