The first two test units are different. The DC resistance is mA, and the insulation resistance is MΩ or even GΩ. Let's talk about the test function:
The purpose of the DC resistance is to check the quality of the windings or windings of the electrical equipment and the integrity of the circuit to find the wire breakage, joint welding, poor contact, and inter-turn short circuit caused by mechanical stress caused by vibration during manufacturing or operation. And other defects. In addition, when the temperature rise test is performed on the generator and the transformer, the temperature value under the corresponding load is also converted according to the DC resistance value under different loads. The Polaris Power Forum not only uses the voltage drop method or the bridge method for measuring the DC resistance.
Measuring the insulation resistance of the equipment is the easiest way to check the insulation state. The megohmmeter is commonly used to measure the insulation resistance. Since the selected megohmmeter voltage is lower than the working voltage of the test object, this test is a non-destructive test, and the operation is safe and simple. From the measured values of the insulation resistance, it is found that the foreign matter which is currently affecting the insulation of the electrical equipment, the local or overall insulation of the insulation is wet and dirty, the insulation oil is seriously deteriorated, the insulation breakdown and severe heat aging are defects.
Therefore, the difference between the insulation resistance and the DC resistance should be well understood now.
Transformer DC winding resistance tester,One of main kinds of Kingrun transformer testing instruments.