1. Short-circuit the secondary windings that are not under test. Connect the CT primary side to P1 and P2, and the CT secondary side S1 and S2 to S1 and S2. After setting the primary test current and the secondary rated voltage and current, close the system power control switch, rotate the mouse to move the cursor to the "Start" option, press the mouse, select "OK", and the test begins.
2. The AC current output from the device to the primary side of the CT continues to increase. The primary current and the secondary loop measured current values are displayed in real time on the screen. When the primary output current or the secondary input current reaches the set current value, the device automatically stops the test, the output current returns to zero, and the ratio is calculated based on the actual measured current.
3. The instrument itself has the same color phase side terminals, that is, CT connects P1 to P1, CT S1 to S1, and the polarity test result is negative polarity. When the cursor is on the "Stop" option and blinking during the experiment, the test automatically exits until the test interface is completed, or you can manually rotate the mouse or press to terminate the test at the end of the experiment by selecting "Return" or "Print and Terminate". The primary side of the test current provides 500.0A, and the secondary rated current is 1A. The actual measured primary current is 503.2A, the secondary terminal current is 0.502A, and the ratio becomes 1002.5:1, with negative polarity.
4. Short-circuit the secondary windings that are not under test. Connect the CT primary side to P1 and P2, and the CT secondary side can be short-circuited or connected to S1 and S2. After setting the primary test current and the secondary rated voltage and current, close the system power control switch, rotate the motion controller to move the cursor to the "Primary Through Current" option, press the mouse, select "OK", and the test begins. The device will gradually increase the current output to the CT primary side to the set value, and then maintain this current output for a period of time to check the integrity of the CT secondary side circuit. The length of this time is related to the current value. When the current density is less than or equal to 200A, the holding time is 5 minutes; when greater than 200A, to protect the CT, the holding duration is only 3 seconds. During the test, the cursor will blink on the "Stop" option until the test is automatically exited after completion, or you can rotate the mouse to manually terminate the test.
The transformer tester is a very common high-voltage power test equipment. Power workers need to be proficient in the test methods of CT ratio and polarity tests in their work to achieve twice the result with half the effort.
