Huazheng HZ-3120A Transformer Winding Resistance Tester DC Resistance Meter

To meet the needs for rapid DC resistance measurement of transformers, our company has developed the HZ-3120A DC Resistance Tester. The instrument incorporates advanced power supply technology and features a compact design, lightweight construction, high output current, excellent repeatability, strong anti-interference capabilities, and comprehensive protection functions. The entire system is controlled by a high-speed microcontroller, offering a high degree of automation along with automatic discharge and discharge alarm functions.

I. Summary

Transformer DC resistance testing is a required procedure during the semi-finished product, finished product, factory testing, installation, overhaul, tap switch change, handover, and preventive maintenance tests performed by the power department in transformer manufacturing. This test checks the quality of the winding joints, identifies any inter-turn short circuits in the windings, and verifies the functionality of the voltage tap switch at each position. It also ensures that the actual position of the tap switch matches the indicated position, checks for broken lead wires, and detects any broken strands in the windings.The instrument provides high-accuracy testing, is easy to operate, and enables rapid measurement of transformer DC resistance.

II. The Key Technical Indexes

item	technical indicators and parameters	remarks
test current	<20mA、1A、2.5A、5A、10A、20A
measuring range	100μΩ～1Ω （20A） 500μΩ～2Ω （10A） 1mΩ～4Ω （5A） 2mΩ～8Ω (2.5A） 5mΩ～20Ω (1A）	accuracy：±(0.2%+2word)
measuring range	10Ω-20KΩ （<20mA）	accuracy：±(0.5%+2word)
meminimum resolution solution	0.1μΩ

indication	liquid crystal display	the resistance shows a valid number of 4 digits
data storage	1000 Groups
work environment	Ambient temperature: 0℃ ~40℃ relative humidity: <90% RH, no condensation
power suply	AC 220V±10V，50Hz±1 Hz	protective tube 5A
maximum power dissipation	500W
external dimensions	main engine：405×230×355（mm） Wiring box：360×260×180（mm）
weight	main engine15KG Wiring box: 5.5KG
test line length	standard configuration13metre	length can be customized

III. Functional Characteristics

1.The entire system is controlled by a high-speed microcontroller, offering a high degree of automation and simple operation.

2.The instrument features advanced power supply technology with multiple current settings, a wide measurement range, and is suitable for measuring the DC resistance of large and medium-sized transformers.

3.The protection functions are comprehensive and can reliably safeguard the instrument from the impact of reverse potential, ensuring more reliable performance.

4.The instrument includes a sound discharge alarm, with clear discharge indicators to reduce the risk of misoperation.

5.Intelligent power management technology ensures that the instrument operates in the minimum power state, effectively saving energy and reducing heat generation.

6.The 7-inch high-brightness touch color LCD provides a clear display even under strong light. It supports full touch-screen operation and allows easy switching between Chinese and English.

7.The instrument is equipped with a calendar clock and power loss storage, capable of storing up to 1000 sets of test data, which can be accessed at any time.

8.The instrument supports Bluetooth communication, RS232 communication, and USB interfaces for computer connectivity and U-disk data storage.

9.The instrument comes with a built-in micro printer, enabling direct printing of test results.

10.The instrument can be controlled via an Android phone or tablet by following the WeChat official account, downloading the dedicated app, and using the special software to control the instrument and upload test data for convenient access.