NDHL-200A Loop Resistance Tester

Product Introduction

       Currently, the conventional QJ44 double-arm DC bridge is widely used in power systems for measuring contact resistance. However, the test current of such bridges is only at the mA level, making it difficult to detect defects caused by reduced cross-sectional area of loop conductors. When measuring the contact resistance of high-voltage switch conductive loops, the presence of oil film and oxide layers between contacts can cause the measured value to be several times larger, failing to reflect the true contact resistance. Therefore, the power industry standard SD301-88 "Handover and Preventive Test Regulations for AC 500KV Power Equipment" and the new edition of "Power Equipment Preventive Test Regulations" specify that the measurement current for circuit breakers and disconnectors should not be less than DC 100A to ensure accurate test results.

       This product is designed based on the new power execution standard DL/T845.4-2004, combining high-frequency switching power supply technology with digital circuit technology. It is suitable for measuring loop resistance in switch control equipment. The test current adopts the nationally recommended DC 100A and 200A. It can directly measure loop resistance at 100A or 200A current, with test results displayed digitally. The instrument offers accurate measurement and stable performance, meeting the requirements for on-site high-voltage switch maintenance by power and supply departments, as well as loop resistance testing in high-voltage switch factories.

Product Features

☆、High Current: Utilizes new power supply technology to output high current continuously for extended periods, overcoming the limitations of pulsed power supplies, and effectively breaking down the oxide layer on switch contacts for reliable test results.
☆、Strong Anti-Interference: Under severe interference conditions, the last digit of the LCD display remains stable within ±1 digit, ensuring stable and repeatable readings.
☆、Long Service Life: Employs high-precision resistors to effectively eliminate the impact of environmental temperature on measurement results, while the use of connectors enhances vibration resistance.
☆、Portable: Compact size and lightweight design.

Technical Parameters

☆、Measurement Range: 1～1999μΩ.
☆、Resolution: 1μΩ.
☆、Test Current: DC 50A, 100A, 150A, 200A, four fixed output ranges.
☆、Measurement Accuracy: 0.5%±1 digit.
☆、Operating Mode: Continuous.
☆、Display: Three-and-a-half-digit LCD.
☆、Power Supply: AC220V±10%, 50Hz.
☆、Operating Environment: Temperature -10℃～40℃, Humidity ≤80% RH.
☆、Dimensions: 380mm×350mm×260mm.
☆、Weight: 5kg (excluding accessories).