What is the main purpose of conducting DC winding resistance tests in transformers?

The main purpose of conducting DC winding resistance tests in transformers is to evaluate performance and detect changes in the current carrying path. This test is essential because it helps identify any issues such as poor connections, damaged windings, or other anomalies that may affect the transformer’s ability to handle electrical currents effectively.

By measuring the resistance in the windings using a DC source, technicians can assess the integrity of the copper or aluminum conductors and any physical changes that may occur over time due to thermal or electrical stress. It also provides insight into the condition of the insulation and helps in diagnosing faults that could potentially lead to more severe problems, ensuring the transformer operates reliably and efficiently in the long term.