Preventive measures for open circuit of current transformer

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

When the secondary open circuit fault of the current transformer occurs, the correct and safe processing method is: power off the high voltage side and process it (recover the open circuit point to the normal circuit state), but this will cause an unplanned power outage; unconventional processing methods Yes: Because there is a discharge phenomenon at the open point when the current transformer is open, it is easier to find. One wire can be used (the wire diameter should conform to 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 fine to use a 2 square wire), first connect one end of the wire to the open coil The grounding terminal is well connected.Use an insulated tool (the insulation of a general screwdriver handle is sufficient) to connect the other end of the wire to the fixed connection point of the open point, to achieve the purpose of shorting the open point, then you can compare It is easy to deal with open points and avoid equipment power outages. This method is not recommended from a safety perspective, but in order to avoid the occurrence of assessment accidents, experienced secondary system staff can do it.

Precautions for open circuit of current transformer secondary 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 switching is necessary, there should be reliable measures to prevent open circuits;

(3) Relay protection and measuring instruments-generally unsuitable current transformers. When they must be used together, the measuring instruments must be connected through an intermediate converter;

(4) The current transformer that has been installed but not used must be shorted and grounded by the terminal of its secondary winding.

(5) The terminals of the secondary circuit of the current transformer should use test terminals

(6) It should be ensured that the connecting wires of the secondary circuit of the current transformer have sufficient mechanical strength.https://www.ctsensorducer.com/