Precautions for On-Site Testing of Transformer Ratio Group Tester

Test: Choose different measurement methods.

Three phase transformation ratio: Measure the transformation ratio of the three phases simultaneously based on the set high and low voltage connection method and connection group.

Group testing: Only measure the connected groups.

Three phase AB, Three phase BC, Three phase CA: Based on the set high and low voltage connection method and connection group, only the selected phase is measured for transformation ratio. This function facilitates measurement and detection only for a certain phase, saving time.

After setting the parameters of the transformer ratio group tester, select the "Test" option and press the "Confirm" button to start the measurement. During the testing process, if the instrument detects a short circuit or high/low voltage reverse connection fault, a fault prompt box will pop up and an alarm will sound, and the measurement will be stopped.

The measurement results are displayed in the middle of the screen, and the operable menu is displayed at the bottom:

Continue testing: Continue measuring according to the set parameters.

Result printing: Print the test results.

Result storage: Store test results on the local machine or on a USB drive.

Select the menu item with the "left and right" keys, and execute the current option with the "confirm" key.

Single phase testing

After selecting the "Single Phase Test" option under the "Main Menu" screen, press the "Confirm" button to enter the "Single Phase Test Parameter Settings" screen.

The screen setting operation is similar to the "Blind Test Function Parameter Setting" screen.

Rated high voltage and rated low voltage: Set the rated high and low voltage values of the tested product. High and low voltage values can be inputted based on actual voltage values or proportionally according to actual situations. After selecting the "single-phase CT" test, the high and low voltage values represent the rated current values on the primary side and the rated current values on the secondary side of the CT. They can be inputted according to the actual current or proportionally according to the actual situation.

Tapping: Set the tapping distance of the tested product.

Rated tap: Set the rated tap position of the tested object. For specimens without a tap position, input 00 or 01 for the rated tap position.

Sample number: Set the sample number for this experiment.

Test: Choose different measurement methods.

Single phase PT: Measure the transformation ratio polarity of PT according to the set parameters.

Single phase CT: Measure the transformation ratio polarity of CT according to the set parameters.

Single phase transformer: Measure the transformation ratio polarity of the single-phase transformer according to the set parameters.

Taking the "single-phase PT" test as an example, after completing the "parameter setting", select the "test" item and press the "confirm" button to start the measurement. During the testing process, if the instrument detects a short circuit or high/low voltage reverse connection fault, a fault prompt box will pop up and an alarm will sound, and the measurement will be stopped.

The operation is similar to the "three-phase ratio test results" screen.

Z-type test

The setting and operation of "Z-type test" and "three-phase test" are similar, and specific operations can refer to the relevant operations of "three-phase test".

Precautions for Transformer Ratio Group Tester Test

For transformers with multiple tap positions, the input of rated high and low voltage values, tap spacing, and rated gear is to enable the test results to automatically calculate the error value and the tap position of the tap switch. If the above parameters are inputted correctly, the ratio error value and specific position of each tap can be automatically calculated during testing, without the need for any further data changes.

For transformers with 19 tap changer positions on load, if the 9, 10, and 11 tap positions are the same value, the instrument should input 9 when entering the rated tap position. After the 12 tap position, the instrument displays a tap position 2 times smaller than the actual position.

The setting of the tap position for the transformer ratio group tester is designed according to the voltage regulation on the high voltage side, assuming that tap 1 is the highest voltage level. If the voltage is designed in reverse or the tap switch is on the low voltage side of the transformer, the displayed tap position is reversed from the actual tap position.

The transformation ratio on the nameplate of a three-phase transformer refers to the ratio of the line voltages of different voltage windings. Therefore, for transformers with different wiring methods, the transformation ratio is related to the turn ratio as follows: the voltage ratio of a three-phase transformer with the same primary and secondary side wiring is equal to the turn ratio; When the primary and secondary side connections are different, the turn ratio of the Y-d connection is equal to the ratio of variation divided by, and the turn ratio of the D-y connection is equal to the ratio of variation multiplied by.

GDZX is a professional manufacturer of secondary protection testing equipment, with a wide variety of instrument and equipment types to choose from. GDZX serves you at 4000-828-027. To learn more, visit GDZX's official website at www.gdzxdl.com.