Product Introduction

       Measuring the DC resistance of transformer windings is a very important test item. In the "Power Equipment Test Regulations," it is ranked second among transformer test items. The regulations stipulate that the DC resistance of transformer windings must be measured during handover, major repairs, minor repairs, tap changer position changes, fault inspections, and pre-tests. The purposes are:

      ① To check the welding quality of internal windings and leads;

      ② To check whether the contacts of the tap changer are in good condition at each position;

      ③ To check if there are any breaks in the windings or leads;

      ④ To verify the correctness of parallel circuits and detect whether there are one or more broken wires in windings made of several parallel conductors;

      ⑤ To check for any short circuits between layers or turns.

       The NDZRT-10A Transformer DC Resistance Tester is designed with microcomputer control and features a large backlit Chinese character LCD screen. It is easy to operate, with a clear and user-friendly interface. The measurement process and instrument status are clearly indicated, reducing the need for operators to memorize excessive procedures. It uses current source linear compensation technology to ensure stable testing, high measurement accuracy, and fast speed, improving measurement efficiency and reducing the workload of operators. The "four-terminal" measurement technique is employed to eliminate measurement errors caused by lead resistance and contact resistance. It has over-voltage protection functionality to guard against back EMF impacts. A panel printer can quickly print measurement results (optional). It is compact, lightweight, and portable. This instrument is suitable for measuring and analyzing inductive low-resistance values of various power transformers and mutual inductor windings.

       This product complies with the requirements of DLT 845.3-2004 "General Technical Conditions for Resistance Measuring Devices Part 3: DC Resistance Testers".

Product Features

☆、Complete all DC resistance data measurements for high and low voltage windings with just one wiring connection;

☆、Three-phase simultaneous measurement plus assisted magnetization method for faster speed and significantly reduced residual magnetic hazards;

☆、Display and print all test data of the transformer's high, medium, and low voltage windings, and automatically calculate

☆、Three-phase unbalance rate, and also automatically convert and print resistance values at rated temperature;

☆、Comprehensive back EMF protection function;

☆、Automatic discharge and discharge indication function to reduce misoperation and ensure equipment and personnel safety;

☆、The instrument can permanently store 500 sets of test data and also use a USB drive for data storage;

☆、The instrument features wide applicable temperature range, high accuracy, shock resistance, anti-interference, and portability.

Technical Parameters

☆、 Output Current:

       Three-phase test: 5A x 2, 2.5A x 2, 1A x 2;

       Single-phase test: 10A, 5A, 1A;

☆、 Measurement Range:

       5A x 2:   1mΩ ～ 1Ω;

       2.5A x 2: 2mΩ ～ 2Ω;

       1A x 2:   5mΩ ～ 5Ω;

       10A:   500μΩ ～ 2Ω;

       5A:   1mΩ～ 4Ω;

       1A:   5mΩ～ 20Ω;

☆、Resolution: 0.1μΩ;

☆、Measurement Accuracy: ±(0.2% reading + 2 digits);

☆、Ambient Temperature: -10℃ ～ 50℃;

☆、Ambient Humidity: ≤85%RH;

☆、Power Supply: AC220±10%;

☆、Power Frequency: 50Hz;