An incident early this year in Whiting, Ind., at one of BP’s largest oil refineries, demonstrated just how catastrophic a transformer failure can be—not only was the plant shut down, but it affected gasoline supplies and prices and oil investments for weeks to come. And it could’ve been more catastrophic than that.
In a recent article in NETA World, Matthew Wallace, president of field services for CBS Field Services, explained the importance of routine inspections and testing of transformers. There are several different ways to test a transformer’s health and reliability, but this article dives deeper into both power factor testing, a measure of the capacitance between isolated areas of the transformer, and sweep frequency response analysis (SFRA), which compares the transformer’s frequency response fingerprint to a baseline to detect internal faults or mechanical issues.
A transformer has several different insulators that need to be evaluated. Power factor testing assesses a transformer’s entire insulating system by testing each of the insulators individually.
It’s important to understand that a low power factor percentage value reflects a healthy insulation system. It’s also critical to understand the key steps of power factor testing, primary test modes, common insulation testing in different types of transformers, and best practices for successful testing.
SFRA compares the transformer’s frequency response fingerprint to a baseline to detect internal faults or mechanical issues. There are a variety of possible issues, including problems in the transformer core, bushings, frequency response, and other areas.
This testing is appropriate in a variety of situations, including immediately after transformer production, before and after transporting the transformer, after commissioning, and after an incident in which electromechanical changes are suspected. Once a transformer has been assembled, electrical tests must be performed to ensure that it is operating as expected. Contact us to learn more about acceptance testing and commissioning.
As a Group CBS company, we also have access to an extensive inventory of parts and electrical power distribution equipment, electrical safety solutions, vacuum interrupters, and more. If you need load tap changer parts or kits for your transformers, use the Circuit Breaker Sales product finder to find just what you need.
Read the full NETA World article here.
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