A DC winding resistance measurement is a common diagnostic test performed on distribution and power transformers. This test can be used to detect internal issues such as shorted turns, burnt or open windings, broken strands, poor connections, and problems associated with On-Load Tap Changers (OLTC) and De-Energized Tap Changers (DETC). Although this test looks simple, in practice, it presents several technical complexities that can cause trouble for field technicians to obtain accurate readings.

The webinar would cover some of the less known facts associated with the DC winding resistance (WR) measurements, diving deeper into topics such as selection of the correct test current, and the importance of compliance voltage during the test. Phenomena such as core saturation, current stabilization, the influence of winding inductance on readings, and the effect of temperature will be explained. Different test techniques and safety procedures will also be covered. 

Additionally, the webinar will also make use of field test results to explain the issues and important factors highlighted above. This webinar will conclude by sharing field cases on how to troubleshoot situations when the readings obtained are outside the NETA and IEEE C57.152 defined limits.

This is a free webinar

All webinar attendees are eligible to receive 1 NETA CTD and 1 PDH or 0.1 CEU.