The standard of miniature transformer transformation ratio and its correct use

When designing, the structure of the miniature transformer will vary greatly due to the different models, so that it can be assembled in different switchgear. Of course, even for the same model, its specifications can be divided into many different types. We mainly choose according to the transformation ratio, the accuracy of the protection coil and the capacity of the secondary coil.

When choosing the transformation ratio of the miniature transformer, you must first understand the actual load rated current. The best current is within the range of 60-80% of the miniature transformer. If the measured current result is compared with the actual current result If there is a relatively large error, the high current will enter the saturation region of the iron core, and the measured data will be meaningless. Therefore, the transformation ratio of the miniature transformer and the ammeter must be kept the same when selecting.

In addition to careful selection of the transformation ratio of the miniature transformer, attention should also be paid to its operation. In order to avoid the burning of the miniature transformer, the circuit breaker must be equipped first to prevent the entire line from power outages and branch faults. There will be no power outages, and the most important thing is to ensure that the branch circuit breakers can be safely tripped.

Then connect the miniature transformer to the back of the circuit breaker. The purpose of this is that when the current transformer fails, the circuit breaker can make the correct response to remove the fault. Perform high-voltage insulation tests on the miniature transformers, so as to find out as soon as possible the degree of insulation aging of the miniature transformers. If the aging is too serious and need to be replaced with new ones in time, we should try our best to avoid the miniature transformers from being burnt out. Lead to the generation of power outages.

If the current suddenly drops during the use of the miniature transformer, the core of the miniature transformer will generate residual magnetism. Therefore, the miniature transformers that have been used for a long time need to be demagnetized, which is to use the excitation current of the primary or secondary winding to exchange the magnetic field for the iron core, that is to say, slowly increase the excitation current from zero. , Make the iron core present a saturated state, and then reduce the excitation current gradually to return to zero, and finally eliminate the remaining magnetism.