Measuring Method of Transformer DC Resistance Tester

Measuring DC resistance is an important item in the oil immersed distribution transformer test. Through the measurement, you can check out the conductive circuit of the device whether the bad contact, poor welding, coil fault and wiring errors and other defects. In the actual measurement of small and medium-sized three phase pad mounted transformer, most of the DC bridge method, when the resistance of the coil in the test more than 1 European commonly used single-arm bridge measurement, 1 euro below the double-arm bridge is measured. In the use of double-arm bridge wiring, the potential of the bridge pile head close to the measured resistance, the current pile head to be connected to the top of the potential pile head. Before measuring, should first estimate the resistance of the coil under test, the bridge override button placed in the appropriate position, the non-measured coil shorted and grounded, and then turn on the power switch charging, to be fully charged after pressing the galvanometer switch, Quickly adjust the measuring arm so that the galvanometer pointer to the middle of the galvanometer scale zero line direction, fine-tuning, to be stationary when the pointer stopped at zero when the resistance value is recorded, this time, the measured coil resistance ratio = × Measure arm resistance. Measurements are completed, the first open galvanometer button, then release the power switch