Surge Testing in Low-Voltage Three-Phase Motors with Random Winding: A Case Study Demonstrating Its Effectiveness

Most of the current standards related to dielectric testing of rotating machines for field maintenance are predominantly focused on stators rated at 2.3kV or higher, leaving low-voltage motors limited to measurements of insulation resistance and winding resistance. However, tests such as surge testing or DC overvoltage testing are powerful tools for diagnosing low-voltage electric motors in the field. Despite their relatively low cost, these motors often present logistical challenges for replacement, and their failure can lead to significant financial losses due to unplanned outages. This article presents a case study that demonstrates the usefulness of performing surge tests on low-voltage motors by applying the criteria recommended for motors rated at 2.3kV or higher.