How to Identify the Parameters of Electric Power Transformers(II)
Second, measure the winding voltage of electric power transformers.
It is the most basic task to utilize an unmarked electric power transformer to identify the primary winding, and to distinguish between the outputs voltage of the secondary winding.
For example: Given an electric power transformer with a total of 10 terminals. Try to judge the winding voltage.
The first step: to distinguish between the numbers of winding groups, draw circuit diagrams.
Use the R × 1 block multimeter to measure, where the similarities of the terminal are the one winding. So you can get: between two interlinked with 3 groups, there is a group of three interlinked, there is a terminal with any other terminal does not pass. According to these measurements, draw the schematic, and mark the number.
From the measurements we can see, there are four windings of the electric power transformer, which label 5, 6, 7 is tap winding, 10 winding terminals and are not any similarities, is the shield leads to terminals.
Step Two: Determine the primary winding.
For step-down power transformers, diameter of primary winding is smaller, and winding turns are more than the secondary winding. Therefore, the largest electric resistance of step-down transformer is the primary winding resistance.
Step Three: Make sure all the secondary winding voltage.
Through the regulator, the primary winding of electric power transformer will be access to alternating current, slowly step up to 220V. Measure the load voltage of each winding, mark the data on the output of electric power transformer. If the electric power transformer no-load state in a long time without fever, indicating that the basic integrity of the transformer performance, but also further validate the decision of the primary winding is correct.