The sweep frequency response analysis (SFRA) test is a powerful and sensitive method for assessing the mechanical and electrical integrity of a transformer core/coil assembly. SFRA includes two tests: an open test and a short-circuit test. Both test a complex network of inductances, capacitances, and resistors, and frequently successfully detect the presence of an electrical failure, including a shorted turn. …
PART 2: FROM CLASSROOM TO CAREER AND BEYOND Part 1 in the Spring issue of NETA World provided a retrospective on the implementation of the NETA Electrical Power Testing Technician (EPTT) curriculum at Long Beach City College (LBCC). That story is important, but it is only half of it. The real measure of success is what happens after students leave …
Transformer Turns Ratio (TTR) testing is a fundamental diagnostic method used to verify transformer winding integrity, tap-changer position, and compliance with nameplate data by comparing measured voltage ratios with theoretical values. This test enables early detection of winding deformation, incorrect internal connections, manufacturing defects, or tap-changer issues. However, when applied to rectifier transformers, complexity increases significantly due to multiple secondary …
The fall of potential (FoP) test to measure the ground impedance of a data center building or substation is commonly specified as part of start-up and commissioning testing. This test procedure is spelled out in IEEE Std. 81, IEEE Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Ground System. To obtain good data,a properly executed …
Electrical safety standards exist to help us work safely on or around electrical equipment. One key element in avoiding electrical hazards is identifying energized parts. NETA Certified Technicians must do everything possible to eliminate their exposure. 1. What is the best information source for selecting isolation points when preparing an isolation plan?a. Schematic diagramb. Single-line diagramc. Visual inspectionsd. Process and …
In October 2025, the American Heart Association (AHA) released the first full revision of its Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) since 2020. The AHA maintains that cardiac arrest claims more lives globally than colorectal cancer, breast cancer, prostate cancer, influenza, pneumonia, auto accidents, HIV, firearms, and house fires combined. Cardiac arrest is an immediate occurrence, …
Recently, I challenged a proprietary AI platform to solve a simple protection problem: Use a CO-9 overcurrent relay to provide backup protection for a 150 MVA transformer; the high-side voltage is 230 kV. Plot the characteristic of the CO-9 versus the transformer damage curve. This was not an especially difficult problem to solve. I wanted to see if it would …
Voltage dividers are simple devices consisting of series circuits that produce two or more lower voltages from a single source voltage via resistances. This is possible because of this mathematical fact: Given a series circuit with multiple resistances, the sum of the absolute values of all voltage drops across each resistance will equal the source voltage. This fact is illustrated …
OK, let’s be honest. When you pull NFPA 70E off the shelf, it’s not exactly something you look forward to reading for entertainment. Yes, it matters. (It matters a lot!) But it’s not built to grab your attention or stick with you. And that’s not a knock on the standard. Consensus standards like NFPA 70E serve a clear purpose: to …
This issue of NETA World’s “Insight and Inspiration” series features Matt Robinson, Director, Safety and Training at Sigma C Power Services. His current role includes the safety and well-being of all personnel within the organization and the responsibility for safe, high-quality operations of the company. In addition to safety, Robinson’s duties make him responsible for the technical and professional development …