The status of the insulation in a rotating machine can be evaluated using various testing techniques. Static tests are performed while the motor is disconnected from the system, typically during manufacturing, commissioning, maintenance, or repairs. The goal of a static test is to provide an accurate picture of the machine’s electrical characteristics. Static tests can often be performed from the …
Partial discharge (PD) is a poorly understood phenomenon that can cause catastrophic failure of electrical assets. It can exist at initial commissioning or occur only after decades of use. The dictionary defines partial discharge as: a flashover of part of the insulation system due to a localized electric field greater than the dielectric withstand capability of that part where the …
Spring 2023 Cover StoryInsulation Assessment Using Non-Invasive TechniquesFeatured StoriesWhat Does Insulation Thermal Class Mean for Electrical Machines?How hot is too hot? Motors and transformers have maximum operating conditions, but can I exceed those ratings on occasion and…Kevin Alewine, Shermco IndustriesElectromagnetic Imperfection Measurements for Stator Core Condition AssessmentThe stator core of a rotating machine is composed of multiple stacked layers to …
Transformer diagnostics play a critical role in ensuring the reliability and longevity of power systems. Understanding the condition of power transformers is essential for preventing unexpected failures and minimizing downtime, which can have significant economic and operational impacts. Sweep frequency response analysis (SFRA) emerges as a powerful tool in transformer diagnostics, offering valuable insights into the transformer’s mechanical integrity, electrical …