Why do we need to wrap the test wire around the column head during DC resistance test?

Why should the test line be wrapped around the column head when testing the DC resistance of the transformer?

Wrapping the test line around the column head is a standard operation in DC resistance testing to improve the accuracy, safety and reliability of the measurement. It can prevent disconnection caused by cable shaking or accidental pulling during the test, and ensure the tightness and contact area of ​​the test line and the transformer winding and line contact points.