DC Resistance Tester, also known as Transformer DC Resistance Tester or Loop Resistance Tester



DC Resistance Tester, also known as Transformer DC Resistance Tester or Loop Resistance Tester, is a precision instrument specifically used to measure the DC resistance value of electrical equipment (mainly transformer windings, motor windings, instrument transformers, switch contacts, etc.). It is one of the core devices in preventive tests and commissioning tests of power equipment, mainly used to detect the connection quality of conductive loops, inter-turn short circuits in windings, and the contact condition of tap changers. The following is a detailed analysis of the DC Resistance Tester: 1. Core Uses Transformer Winding Test: Check the welding quality of internal conductors in transformer windings, strand breakage, inter-turn short circuits, and whether the contact of each position of the tap changer is good. Motor and Generator Test: Measure the DC resistance of stator and rotor windings, judge the balance of three-phase resistance, and discover potential inter-turn short circuits or poor connections. Switchgear Test: Measure the conductive loop resistance of circuit breakers, disconnectors, and GIS combined appliances to evaluate contact wear or oxidation (usually using a large-current micro-ohmmeter). Cable and Busbar Test: Detect the continuity of long-distance cables or busbars and the resistance of connection points. 2. Working Principle The DC Resistance Tester is based on Ohm's law (