The fundamental principles of electrical ground testing were laid down in the early 20th century, with much of the pioneering work done by Frank Wenner of the U.S. Geological Survey. The most basic and widely used method for measuring soil resistivity bears his name. These principles still underlie ground testing into the present century, but many improvements have been made …
You may have seen my LinkedIn post about this, but we’ll expand further with some examples to highlight this resource for a better understanding of NFPA 70E. There were two points to the message: Edited by Dean Austin, Chris Coache, and Corey Hannahs, the authors do a great job of providing usable information to us, the electrical workers. It was …
As milestones go, January 16, 2023, might well be considered a significant point in development within our industry. That is when NFPA 70B became effective as a standard recognized by the American National Standards Institute (ANSI). While long accepted as an industry-leading recommended practice, ANSI certification brings changes to NFPA 70B. In this edition of NETA World, our contributors …
The 2023 edition of NFPA 70B saw it converted from a recommended practice to the Standard for Electrical Equipment Maintenance. This NFPA 70B update will continue to work in conjunction with ANSI/NETA standards and other NFPA standards to provide details on power system maintenance to NETA companies and NETA technicians. 1. Which option does NFPA 70B define as “a …
The purpose of using temporary protective grounds is to protect personnel servicing the equipment and to create a safe work environment. Before servicing a piece of electrical equipment, it is important to ensure that it is in a safe state and to verify zero voltage before applying temporary protective grounds. In many situations, more than one set of grounds or …
This article demonstrates how current transformer (CT) saturation can adversely affect transformer differential protection and how to easily mitigate its effects via inbuilt relay functions. We provide calculations and simulation for a three-phase fault on the low side of the transformer just external to the CTs. APPLICATION The application is for a three-phase delta-wye connected transformer serving station at a …
Numerous articles have been written about NFPA 70B in recent months following the recommended practice becoming a standard. All this chatter and renewed interest is coming from the perception — and rightfully so — that failure to perform minimum electrical maintenance could lead to OSHA fines. I’d like to believe that facilities that did not previously have an electrical maintenance …