How Multi-Function Numerical Protection Relays Use Symmetrical Components

Steve Turner, Arizona Public Service Company Columns, Relay Column, Summer 2019 Columns

Multi-function protection relays calculate and use symmetrical components to enhance their performance during system faults. This can be illustrated in two specific examples: (1) zero-sequence current elimination for transformer differential protection and (2) negative-sequence current detection to inhibit out-of-step blocking. Zigzag Transformer Inside Transformer Differential Zone A shunt-connected zigzag transformer provides a zero-sequence current sink for ungrounded systems such as …

Arc Rated Clothing and Electrical Hazard Footwear

Paul Chamberlain, American Electrical Testing Co., LLC Columns, Safety Corner, Summer 2019 Columns

Everyone wears clothes, at least when out in public. However, not everyone needs to wear clothes specially designed and tested to protect them from hazards they could find in their workplace. If your employees work on or near electric power, generation, transmission, and distribution equipment, specialized clothing is necessary for certain tasks.  OSHA 29 CFR 1910.269 states that employers must …

Using NFPA 70E to Stay Alive

James R. White, Shermco Industries Columns, Summer 2019 Columns, Tech Quiz

This month’s Tech Quiz takes a bit different look at NFPA 70E requirements. What is involved in electrical testing? As with most things, it’s not as simple as it may seem. 1. If you are a crew leader, what is the first thing you would do to test a transformer? a. De-energize it b. Isolate it by lockout/tagout (LOTO) c. …

10 Design Features for Electrical Safety

Jeffrey R. Jowett, Megger Columns, Summer 2019 Columns, Tech Tips

The National Fire Protection Association (NFPA®) revised its NFPA 70E, Standard for Electrical Safety in the Workplace in 2018 “to assist OSHA in preparing an electrical safety standard that would serve OSHA’s needs and that could be expeditiously promulgated through the provisions of…the Occupational Safety and Health Act.” Responsible electrical test instrumentation manufacturers accept 70E as a valuable guideline as …

A Guide to NFPA 70E

Ron Widup and James (Jim) R. White Columns, NFPA 70E and NETA, Summer 2019 Columns

Many companies and people rely on NFPA 70E to guide them as they develop and implement electrical safe work practices. They look at a line or possibly a paragraph or two and believe they have the gist of the issue. Maybe, but they often misinterpret what they read or implement it incorrectly. Unfortunately, there’s a plethora of misleading or incorrect …

NFPA 70E and Electrical Testing

Ron Widup and James (Jim) R. White Features, Summer 2019 Features

In 1976, OSHA asked the National Fire Protection Association (NFPA) to develop a safety standard it could consult to develop its own electrical safety regulations. This was the start of NFPA 70E. At that time, Chapter 1 included the safety portions of the National Electric Code (NEC) broken out for compliance officers to use in the field. Not many people …

Electrical Safety Program Principles: Are They in Your Electrical Safety Program?

Terry Becker, TW Becker Electrical Safety Consulting Inc. Features, Summer 2019 Features

NFPA 70E Article 110.1 and CSA Z462 Clause 4.1.6 outline the requirements to implement a compliant electrical safety program as part of an employer’s overall occupational health and safety management system (OHSMS).  ANSI Z10, Occupational Health & Safety Management Systems (for the US) and CSA Z1000, Occupational health and safety manage-ment (Canada) outline general requirements and specific content for an …

High-Voltage Arc Flash Assessment and Applications, Part 1

Albert Marroquin, Abdur Rehman, and Ali Madani Cover Story, Summer 2019 Cover Story

Protecting utility workers and other working personnel who are exposed to line-to-line voltages above 15kV at live electricity installations is critical. For this reason and to ensure compliance with OSHA regulations, arc flash hazards must be evaluated and studied for every facility with an electrical installation. An arc flash produces extremely high temperatures, intense heat flux and radiation, high sound …

ANSI/NETA Standards Update

NETA World Staff Specifications & Standards, Spring 2019 Specifications & Standards

          ANSI/NETA MTS-2019 New Edition ANSI/NETA MTS, Standard for Maintenance Testing Specifications for Electrical Power Equipment and Systems, 2015 Edition, has been revised. ANSI/NETA MTS-2019 was approved by ANSI as an American National Standard on February 7, 2019. The revised edition of ANSI/NETA MTS, scheduled for release in March 2019, features new content including Online Partial Discharge …