TD2540A DC Resistance Tester

1、 Overview

This inductive load DC resistance tester, with a high-speed microcontroller as the core, adopts high-speed A/D converter and programmable current source technology, achieving * measurement effect and highly automated measurement function. It has high accuracy, wide measurement range, stable data, good repeatability, strong resistance, and complete protection function. Features such as fast charging and discharging speed. This instrument.TD2540A DC Resistance TesterSmall in size, lightweight, and easy to carry, it is the new generation product for transformer DC resistance testing.

2、 Main functions and features
1. Using a high-speed 16 bit A/D converter, the measurement data is stable and has good repeatability.
2. Automatic programmable current source technology, the current source has a total of 1000 current gears, which are automatically controlled by an internal microcontroller based on the measured resistance, thus achieving a relatively wide measurement range and measurement state without the need for manual switching of current gears.
3. Fast response speed, can directly switch to tap changer in measurement state, the instrument will automatically prompt, and the new resistance value will be displayed quickly.
4. Highly intelligent design, clever function settings *, can automatically determine faults such as virtual connection and disconnection of test lines.
5. The protection function is complete and can reliably protect against the impact of back electromotive force on the instrument, with automatic discharge indication function.
6. It can display the measured current and measurement time.
7. Intelligent power management technology can effectively reduce internal heating of instruments.
8. Can store 120 measurement data without loss in case of power failure.
9. All Chinese character menus and operation prompts are intuitive and convenient.

IIITD2540A DC Resistance TesterMain technical indicators
1. The main technical indicators are shown in the table below:
Measurement range: 1m Ω -2K Ω
Output current: 0-10A
Measurement accuracy: 0.2% ± 2 words
2High resolution: 1u Ω
3. Working power supply: AC220V ± 10%
4. Environmental temperature: -10 ∽ 40 ℃
5. Volume: 370 × 245 × 130mm (10A type)
6. Weight: 7Kg (10A type)

4、 Precautions

1. Before testing the no-load tap changer of the transformer, it must be reset. After the discharge is completed, the alarm sound should stop for more than 10 seconds before switching the tap changer.

2. Before disconnecting, be sure to wait for the discharge to end and the alarm sound to stop. Wait for more than 10 seconds before disconnecting to ensure the discharge of the charge.

3. When selecting the current, refer to the range in the technical specifications column and do not use it beyond or below the range. When the current exceeds the preset value, the instrument remains in the "charging" state. When the range is insufficient, it displays' current too low '. When these two states occur, confirm the range and select the appropriate current for testing.

4. Pay attention to the range when using the magnetic assist method. Because two high-voltage coils are connected in parallel and one is connected in series, 1.5 times the resistance of the high-voltage coil is added to the entire testing circuit, and the range selection needs to be taken into account. If the output current cannot reach the set value or is unstable when using beyond the range.

5. When the short contacts of the three wires of the magnetic assist method are removed after discharge, there may be residual current, and there may be ignition and discharge during removal, which is a normal phenomenon.

6. When connecting the test clip to the lead out terminal of the transformer winding, it is important to note that the lead out terminal is exposed to the air and covered with an oxide film on its surface, which may cause unstable or inaccurate measurement results. Therefore, when wiring, it is important to clean the oxide film or twist the test clip a few times after connecting it to the lead out terminal to cut through the oxide film and ensure a good connection.