How to conduct CT ratio test with transformer tester? Transformer tester can perform CT and PT tests, with advantages of high speed and high accuracy, and is currently the mainstream equipment for transformer calibration. In this article, Yitiancheng Electric mainly takes YTC8750E transformer tester as an example to briefly explain the test method of transformer.
On the main menu interface, rotate the mouse to move the cursor to the CT Test option, press the rotary mouse to select CT Ratio to enter the ratio polarity test setting interface (as shown below). Move the cursor to Return to Upper Level , press the mouse to return to the main menu.
Interface Description:
Primary Output Current
The maximum primary current to be output, range (0 - 1000) A.
Automatic Test
After setting the output current, press this key to start the automatic test.
Error Test
Take values according to the rated primary: 1%, 5%, 20%, 100%, 120%, and simultaneously display phase error and ratio error.
Secondary Circuit
Output the set primary current, maintain for 5 minutes (maximum 200A).
Note:
Before the test, please check whether the rated ratio in Parameter Settings is consistent with the rated ratio of the CT under test. If inconsistent, it will lead to errors in ratio and ratio error.
Wiring Method:
Use the red and black high-current wires from the wire kit, connect one end to the CT primary, and the other end to the L1 and L2 terminals of the instrument.
Use the red and black secondary wires from the wire kit, connect one end to the CT secondary, and the other end to the K1 and K2 terminals of the instrument.
Automatic Test:
After setting the primary output current, click Automatic Test and select OK to start the test. The instrument will automatically increase the current according to the set value. After the test stops, it will automatically calculate the ratio, phase error, ratio error, and polarity.
Save
Store the current test data. Click and then select OK.
Click to print the test results.
Error Test
The error test current increase is based on the rated primary in the parameter settings: 1%, 5%, 20%, 100%, 120%, and displays the phase error and ratio error results.
The wiring method is the same as the automatic test.
Secondary Circuit
The secondary circuit interface is shown below.
Maintain the output current at the set value for 5 minutes (maximum 200A).
Secondary Load
After wiring, select Secondary Load , set the rated secondary, then select OK. The instrument will automatically calculate the impedance and load.
When data needs to be modified, move the cursor to the option to be modified, press the mouse to enter the hundreds or tens digit modification operation (the cursor shrinks to the digit being modified), rotate the mouse left or right to increase or decrease that digit. Press the mouse to confirm the modification of that digit and enter the next digit modification, similarly rotate the mouse left or right to increase or decrease that digit. After modifying digit by digit, the cursor enlarges to the full cursor, exiting the data modification operation. At this time, rotate the mouse to move the cursor away.
The CT test of the transformer is a small item among the many test functions of the transformer, but power workers can draw inferences from this test item, master it thoroughly, and conduct tests of other items. During the test,
