Typically, multi-function numerical generator protection relays are now used to provide out-of-step tripping (OST) for large unit-connected generators. However, some users prefer to maintain older existing infrastructure, such as electromechanical relays. 78 OST protection must meet PRC-026-2 Criterion A of Attachment B requirements as follows: PRC-026 Criterion A of Attachment B indicates that a 78 impedance-based out-of-step protection function should …
If you’ve worked on transformers in renewable energy circuits, as I have for the past six months, you’ve likely seen many—perhaps most—equipped with electrostatic shields, grounded copper or aluminum sheets wedged between the high- and low-side windings. The existence of these shields inside transformers is normally (but not always) readily identifiable via the unit data plates (Figure 1). Some affirm …
We work around electricity every day. We are exposed to hazards every day. But what’s the most dangerous task YOU do every day? DANGEROUS TASKS The Starting Point: Turn It Off! My guess is you treat switching operations like surgery—plan the task, determine the proper shutdown sequence, see which loads are affected, check the one-line diagrams, verify the labels, double-check …
As we open 2026, I am proud to reflect on what was one of the most consequential years in NETA’s history. In 2025, our Association advanced its mission of promoting safety, reliability, and technical excellence across the electrical power testing industry at a time when our work has never been more critical. Last year marked the release of ANSI/NETA ATS–2025, …
As testers, where should we start? The standards! For grounding testing, the industry reference is IEEE Std. 81, Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Grounding System. As with most standards, familiarity and interpretation are key. It can be a challenge to understand the intent, methods, and implementation of the prescribed testing. Fall of Potential …
All electrical equipment has a finite lifespan. Recognizing the signs of aging and understanding how to assess equipment health is essential. As NETA Certified Technicians, we play a critical role in helping to extend the operational life of electrical systems by implementing proactive maintenance strategies that enable our customers to maximize performance and reliability for as long as possible. 1. …
The most common injury in any industry is a slip, trip, or fall. Whether a fall occurs on the same level — or worse, from a higher level — any fall can cause significant injury, resulting in production downtime, reduced maintenance activity, loss or reduction of wages for the employee, loss of profit for the company, trips to doctors and …
Stator ground faults are one of the most common disturbances for high-impedance grounded generators. A resistor is connected across the secondary of a single-phase distribution transformer connected from the machine neutral to ground to insert the high-impedance ground. The purpose of the high-impedance ground (Figure 1) is to limit the magnitude of single line-to-ground fault current flowing in the stator …
The days of low-voltage breakers being simple devices with basic overcurrent protection are long gone. Back then, the biggest challenge was to figure out how to defeat a ground fault or remember which jumper disabled thermal memory. Today, manufacturers are leveraging digital technology to add layers of protection and functionality. These advancements can quickly derail a routine day of testing …
If you work around electricity, your career…and maybe your life…depends on what’s hidden in a bowl of alphabet soup. I’m talking about electrical acronyms: NFPA, OSHA, 70E, 70B, NETA, NEC, Z462, EASA, and so on. At first, they may sound like code meant to confuse you. But once you crack that code, everything about your job makes more sense…and becomes …