This article reviews current electrical testing methods and trends in the operational health of electric motors in the context of successful predictive maintenance programs. It explains the concepts of static motor testing — testing a motor that is not running — as well as dynamic motor monitoring, which involves analyzing motors while they are in service or operating within their …
In the upcoming years, changes to the existing NERC standards and approved models will be proposed. These changes will impact the synchronous generator (SG) compliance approach and representation. This article outlines proposed changes relevant to generator owners and the impacts on compliance efforts for two such standards: MOD-025 and PRC-019. We also briefly discuss the newly proposed generator model, GENQEC, …
Power cables are important assets in transmission networks for the reliable operation of power systems. To prevent catastrophic failures in underground cables and terminations, it is important to know how to leverage the various types of available sensors that can detect PD and locate the source so that appropriate action can be taken to avoid in-service failures. This article answers …
How hot is too hot? Motors and transformers have maximum operating conditions, but can I exceed those ratings on occasion and not damage the equipment? In my years as an electrical insulation application consultant, the most common questions posed by end users regard insulation thermal classes and what effect they have on machinery reliability and life expectancy. Many articles have …
The stator core of a rotating machine is composed of multiple stacked layers to minimize eddy current losses. A short between two or more layers leads to higher local eddy currents. This in turn can lead to local hot spots, which in a worst-case scenario can cause a partial core melt and eventually damage the machine. A ring flux (or …
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 …
ANSI/NETA MTS–2019 REVISION IN PROCESS A standards revision is in process for ANSI/NETA–2019, Standard for Maintenance Testing Specifications for Electrical Power Equipment and Systems, to be released in the Spring of 2023. The recirculation ballot and public comment period ended on December 18, 2022. The Standards Review Council will review all comments for consideration by the end of January. The …
Locating faults in buried or concealed cable is one of the most demanding, inventive, and interesting chores in all of electrical maintenance. The operator’s skills, knowledge, and ingenuity are paramount. When the power goes out, an entire facility, neighborhood, or community can be abruptly shut down without warning. Normally, this goes largely unnoticed as the utility seamlessly switches to another …
Rotating machinery is an essential component of most power systems, from compressors in petrochemical plants to turbines in hydroelectric generation plants. NETA Certified Technicians must be familiar with the maintenance and possible failure means of various rotating machines. Virginia Balitski, CET, Manager – Training and Development, has worked for Magna IV Engineering since 2006. Virginia started her career as …
Performing condition analysis or maintenance on rotating machinery is a hazardous task that requires an experienced individual who is capable of performing the duty and possesses a solid ability to identify any potential hazards and mitigate their risks. Inadvertent injuries, such as crushed hands, arms, severed fingers, blindness, or death can occur from rotating machinery if extreme caution is not …