Even in the worst of times, when everything in the world appears to be going wrong, healthcare facilities must get it right. Society has a life-or-death dependency upon hospitals being open and fully capable of treating any needs that arise. The COVID-19 pandemic is an excellent example of our reliance on the healthcare industry. As the virus spread worldwide, hospitals …
Protective relays are the brain and intelligence behind a medium-voltage distribution system (Figure 1). They serve as critical infrastructure for proper medium-voltage system operation, protection, and system reliability. Upgrading electromechanical to microprocessor relays and mitigating arc flash hazards in a medium-voltage system can be performed in synergy to achieve optimal system reliability and safety. KEEPING UP WITH TECHNOLOGY With electromechanical …
Partial discharge (PD) testing is routinely used on all types of medium- and high-voltage equipment as a factory quality assurance test for electrical insulation and as a tool to detect deterioration in the electrical insulation of operating equipment. Today, dozens of vendors supply PD instruments, but the first PD tests were made by researchers over a century ago in an …
In commercial and industrial power systems, harmonic currents can create a variety of issues, including increased power losses and potential damage to equipment. This article describes the various types of power losses associated with neutral and ground harmonic currents with a focus on resistive losses, transformer losses, and dielectric losses in distribution and power factor correction capacitors, and how these …
Circuit breakers in electrical systems play a critical role in ensuring personnel safety, equipment, and systems reliability. These protective devices are designed to interrupt the flow of electrical current in the event of a fault, preventing potential hazards such as electrical fires and equipment damage. Low-voltage circuit breakers encompass a range of types, including insulated case circuit breakers (ICCBs)/molded case …
NETA’s ANSI/NETA standards are some of the most useful publications for the electrical power testing industry. The standards provide guidance to those trying to maintain our fragile electrical infrastructure. Safety, reliability, and quality were the core principles that drove NETA to pursue the creation of a set of industry standards for electrical power equipment and systems. NETA is accredited by …
Transformer differential protection (ANSI 87), which operates on Kirchhoff’s Current Law (KCL), is one of the most common protection methods for large power transformers. This method was first implemented using electromechanical relays built with instrument transformers and other electrical components to convert secondary currents from amperes to per-unit to apply KCL properly. For a detailed explanation of the operation of …
Medium-voltage (MV) cables serve as the backbone of a distribution system, playing a vital role in ensuring the reliable supply of electricity. However, maintaining this extensive network comes at a significant cost for operators. Off-line partial discharge (PD) testing emerges as a valuable tool in managing operating costs and enhancing the reliability of MV cable systems. By transitioning from traditional …
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, …