The main purpose of measuring DC resistance is to check the following aspects of the transformer:

1. Whether the welding or mechanical connection at the winding wire connection is good, and whether there are any welding or connection defects.

2. Whether the connection between the lead and the sleeve, the lead and the tap changer is good, and whether the welding or mechanical connection between the lead and the lead is good.

3. Whether the specifications and resistivity of the wire meet the requirements.

4. Whether the DC resistance of each phase winding is balanced.

The temperature rise of transformer windings is calculated based on the cold resistance of the windings before the temperature rise test and the hot resistance at the moment of power disconnection after the temperature rise test, so the resistance needs to be measured during the temperature rise test.

6. Used as basic data for calculating load loss.

HZ-3110B Transformer DC Winding Resistance Tester 10A