DC Resistance Tester Wiring Diagram
The transformer DC resistance tester is a new generation of fast tester that integrates the magnetic assist method test and three-phase simultaneous test. The DC resistance tester wiring diagram is an ideal device for measuring the DC resistance of large power transformers.
I. Main Features
?The DC resistance tester wiring diagram connects all high and low voltage current and potential test leads to the transformer at once, so there is no need to switch test leads during the test;
?For star-connected winding tests, the instrument can adopt a three-phase simultaneous test method to test the resistance of phases A0, B0, and C0, saving test time;
?When testing the low voltage side of a three-phase five-column transformer with internal delta connection, the instrument uses an automatic magnetic assist method internally, which is faster than directly using a large current test and reduces the harm caused by large residual magnetism after high current testing;
?Displays and prints all test data of the high, medium, and low voltage windings of the transformer, and automatically calculates the three-phase unbalance rate. It can also print the resistance value converted to the rated temperature;
?During three-phase testing, the A0 data is tested first, then the three-phase simultaneous test is performed, solving the problem that the neutral point lead resistance cannot be tested during three-phase simultaneous testing, and the test data is closer to the single-phase test value;
?Has a complete back-EMF protection function;
?The DC resistance tester wiring diagram instrument can store 200 test data records internally (expandable), and can also use a USB flash drive to store data for easy import into a computer for processing;
?The instrument has the characteristics of wide applicable temperature, high precision, shock resistance, anti-interference, and portability.
II. Main Technical Indicators and Usage Conditions
1. Technical Indicators
1) Test current:
Three-phase test: 5A+5A 1A+1A two gears
Single-phase test: 10A, 5A, 1A three gears
2) Test range: 10A: 500.0uΩ ~1Ω
5A: 10mΩ ~4Ω 5A+5A 10mΩ ~1Ω
1A: 100mΩ ~20Ω 1A+1A 100mΩ ~5Ω
3) Minimum resolution: 0.1uΩ
4) Accuracy: ±(0.2%+2 digits)
5) Dimensions: 435mm×300mm×225mm
6) Weight: 12kg (excluding test leads)
2. Usage Conditions
1) Ambient temperature: -10℃ ~ 50℃
2) Ambient humidity: ≤ 85% RH
3) Working power supply: AC220V ± 10%
4) Power frequency: (50±1) Hz
III. Panel Function Introduction
1. LCD screen: displays real-time clock, operation menu, test data, and simple operation instructions.
2. Buttons: Use the six buttons "↑", "↓", "←", "→", "Confirm", and "Return" to control all functions of the instrument. Basic functions: "←" and "→" keys move the cursor, "↑" and "↓" keys modify values (the tap position can be modified during testing), "Confirm" key executes the selected operation, and "Return" key goes back to the previous page.
3. Power switch: AC220V power switch.
4. Terminal: grounding terminal.
5. Wiring terminals (high voltage): connect to the high voltage side or medium voltage side of the tested transformer.
6. Wiring terminals (low voltage): connect to the low voltage side of the tested transformer. DC resistance tester wiring diagram
7. Printer: prints test data.
8. USB: USB flash drive interface.
9. RS232: for manufacturer upgrades.
IV. Instrument Wiring
1. DC resistance tester wiring diagram: Use the power cord to connect the instrument to an external AC 220V power supply, and use the grounding wire to connect the grounding terminal to the earth.
2. DC resistance tester wiring diagram: When testing a two-winding transformer, connect the four test clamps (yellow, green, red, black) of the high voltage test lead (the longer one) to the A, B, C, and O bushings on the high voltage side respectively. If there are only three bushings A, B, and C, the black test clamp can be left floating; connect the other end of the test lead to the corresponding wiring terminals on the instrument. Connect the four test clamps (yellow, green, red, black) of the low voltage test lead (the shorter one) to the a, b, c, and o bushings on the low voltage side respectively. If there are only three bushings a, b, and c, the black test clamp can be left floating; connect the other end of the test lead to the corresponding wiring terminals on the instrument.
Note: No need to switch leads during the entire testing process.
3. For a three-winding transformer, after testing the high and low voltage windings, you can switch the four test clamps of the high voltage test lead (the longer one) to the medium voltage side for testing.
4. For a single-phase transformer, use the yellow and black test clamps of the high voltage test lead (the longer one) to connect to the high voltage side of the single-phase transformer, and the yellow and black test clamps of the low voltage test lead (the shorter one) to connect to the low voltage side of the single-phase transformer.
5. The dedicated test leads provided with the instrument have the current and voltage lines designed into the same clamp, making wiring simple and convenient.
V. Usage Instructions
1. Plug in the power cord, and after the instrument is powered on, the following screen will be displayed:
DC resistance tester wiring diagram: On this interface, because the external test sample is being detected, the keyboard is locked. After the external test sample detection is completed, the keyboard is unlocked, and area 3 will prompt to press the confirm key to enter the main menu.
2. Main menu interface
Use the "↑" and "↓" keys to select the menu. Select the "DC Resistance Test" or "Temperature Rise Test" menu, and press the confirm key to enter the test parameter setting interface.
3. Parameter setting interface:
Use the "←" and "→" keys to move the cursor (the cursor can move cyclically for quick selection), and the "↑" and "↓" keys to modify the setting parameters. Press the "Confirm" key to save the current parameters and enter the next interface (Figure 5 or Figure 6). Press the "Return" key to return to the previous interface.
4. Test winding selection interface
Use the "↑" and "↓" keys to move the cursor, and press the confirm key to enter the selected menu. Press the "Return" key to return to the previous interface.
If the "Number of transformer windings" is set to 3 in Figure 4, the instrument will enter the interface shown in Figure 6:
Use the "↑" and "↓" keys to move the cursor, and press the confirm key to enter the selected menu. Press the "Return" key to return to the previous interface.
If the "Number of transformer phases" is set to 3 in the parameter setting interface, the instrument will enter the test scheme selection interface;
If the "Number of transformer phases" is set to 1 in the parameter setting interface, the instrument will directly enter the start test interface.
5. DC resistance tester wiring diagram: Test scheme selection interface
Use the "↑", "↓", "←", and "→" keys to move the cursor. Press the confirm key to enter the test interface according to the selected menu. Press the "Return" key to return to the previous interface.
6. Test interface (as shown in Figures 9, 10, and 11):
If "Single-phase test..." is selected in Figure 7 or Figure 8, the instrument will enter the interface shown in Figure 9:
Use the "←" and "→" keys to move the cursor (the cursor can move cyclically for quick selection), and the "↑" and "↓" keys to modify parameters (tap position and test current are modifiable items). Press the "Confirm" key to start the test. Press the "Return" key to return to the previous interface.
If "Three-phase test..." is selected in Figure 7 or Figure 8, the instrument will enter the interface shown in Figure 10:
Use the "←" and "→" keys to move the cursor (the cursor can move cyclically for quick selection), and the "↑" and "↓" keys to modify parameters (tap position and test current are modifiable items). Press the "Confirm" key to start the test. Press the "Return" key to return to the previous interface.
If the magnetic assist method test is selected in Figure 8, the instrument will enter the interface shown in Figure 11:
Use the "←" and "→" keys to move the cursor (the cursor can move cyclically for quick selection), and the "↑" and "↓" keys to modify parameters (tap position, test phase, and test current are all modifiable items). Press the "Confirm" key to test according to the current parameters. Press the "Return" key to return to the previous interface.
7. DC resistance tester wiring diagram: Test process
(1) Single-phase test interface
If the "Start Test" button is clicked in Figure 9, the instrument will display the words "Charging" and show the current:
When the charging current is stable, the instrument automatically calculates and displays the winding resistance.
Note: On this interface, you can press the confirm key at any time to stop the test.
Use the "←" and "→" keys to move the cursor (the cursor can move cyclically for quick selection), and the "↑" and "↓" keys to modify the tap position. Press the confirm key to execute the selected operation. After the test data is stable, press "Print" to print the measured values displayed on the screen along with the previously set parameters. If you press "Save", a save window will pop up to prompt you to select the memory (as shown in Figure 14):
DC resistance tester wiring diagram: Use the "↑" and "↓" keys to move the cursor, and press the confirm key to save. After the save task is completed, the instrument automatically returns to the test interface. You can also choose not to save and press the "Return" key to return to the test interface.
If it is an on-load tap changer winding, you can switch to the next tap position, and the screen data will automatically track the test. Use the "↑" and "↓" keys to change the tap position on the screen. After the test data is stable, press "Save" to save the data to the set tap position. If you have doubts about the data displayed on the screen, you can press "Repeat Test" to re-test the current and voltage signals and calculate the resistance value. After testing a set of data, press "Stop Test", and the screen will prompt "Discharging" and display the discharge current. After the discharge is completed, the screen returns to the test interface, where you can change the test current or tap position (or test phase in magnetic assist method) to continue testing or return to the previous interface to select other items for testing.
(2) Three-phase test interface
When the charging current is stable, the instrument automatically calculates and displays the winding resistance.
Note: On this interface, you can press the confirm key at any time to stop the test.
