Earth Resistivity Test Methods and Evaluations

Jeffrey R. Jowett Columns, Summer 2021 Columns, Tech Tips

Ground testing is often thought of as ground electrode testing: the measurement of the resistance associated with a particular rod or grounding system. A useful corollary to this is soil resistivity testing. Resistivity is the electrical property of soil itself that determines how well it can carry current. It varies enormously (Table 1) depending on physical and chemical composition, moisture, …

Medium-Voltage Power System Components

James R. White Columns, Summer 2021 Columns, Tech Quiz

The Tech Quiz questions for this issue concern medium-voltage power system components. FREE QUESTION! What is medium-voltage? Great question, as there are varying answers from NETA, NEMA, NFPA, and IEEE. NETA’s Standards Review Council has defined and classified medium-voltage within the NETA standards as “a class of nominal system voltages greater than 1,000 volts and less than 100,000 volts,” which …

Medium-Voltage Circuit Breaker Condition Analysis and Hazard Awareness Update

Paul Chamberlain and Scott Blizard Columns, Safety Corner, Summer 2021 Columns

When performing condition analysis on medium-voltage circuit breakers located in metal-clad switchgear, it is necessary to be aware of all potential hazards. The person performing the condition analysis must be qualified to perform the task and have a solid understanding of each possible hazard they may encounter as well as ways to minimize the risks. To better understand the hazards …

The Lights are Still On!

Don A. Genutis Columns, In the Field, Summer 2021 Columns

The technician’s job is usually to ensure the lights are on, but we often need to shut a facility down to perform much needed outage-based maintenance. This switching activity is often straightforward, but when the electrical system is complex and several issues exist, unexpected events can occur. Our team was recently fortunate to be awarded a major contract to provide …

Best Practices for Setting Transformer Differential Protection CT Compensation

Steve Turner Columns, Relay Column, Summer 2021 Columns

Historically, CT connections compensated for the phase shift across a transformer when applying differential protection prior to the advent of numerical transformer protection relays. For example, a delta-wye transformer would have wye connected CTs on the delta side and delta connected CTs on the wye side. The delta connected CTs have the same connection as the transformer delta connected winding …

Key Points of NFPA 70E’s Safe Work Practices

Ron Widup and James (Jim) R. White Columns, NFPA 70E and NETA, Summer 2021 Columns

At 5:45 AM on a particularly cold winter day, an industrial manufacturing plant experienced a significant electrical fault event on a 15kV substation that feeds power to approximately 30% of the manufacturing operations. FAULT ON FEEDER M1A: WHAT HAPPENED? The main circuit breaker in one of the plant’s three medium-voltage substations experienced a fault, arc flash event, and subsequent trip …

COVID-19 and the Birth of PowerTest TV

Scott A. Blizard President's Desk, Columns, Summer 2021 Columns

In this issue of NETA World, we focus on medium-voltage circuit breaker test methods and the analysis of the resulting test data from those methods. Be sure to check out “Power Factoring Medium-Voltage Breakers” by Rick Youngblood of Electrical Maintenance & Testing and “The Why of Medium-Voltage Circuit Breaker Testing” by Paul Grein of Group CBS Testing for a good …

Low-Voltage Circuit Breakers

James R. White Columns, Spring 2021 Columns, Tech Quiz

This edition of the Tech Quiz discusses one thing we all deal with, either at home or at work: low-voltage circuit breakers. Typically, they can last for years without causing problems, but they do require some maintenance and care. Continue on to find out what’s in store for you! 1. When the topic of low-voltage circuit breakers comes up, what …

Portable and Mobile Ladder Safety

Paul Chamberlain Columns, Safety Corner, Spring 2021 Columns

Falls from ladders account for 20% of all fatalities and lost-workday injuries in general industry according to Occupational Safety and Health Administration (OSHA) statistics. Ensuring that all ladders meet OSHA and American National Standards Institute (ANSI) standards is critical in mitigating this statistic. OSHA Regulatory Requirements OSHA published an update to its walking-working surface rule (Subpart D) for general industry …

Animal Damage in the Field

Don A. Genutis Columns, In the Field, Spring 2021 Columns

Emergencies always seem to occur on Fridays and weekends, and true to form, a panicked customer called about a power outage to a significant portion of a college campus on a Friday morning. It seemed likely to be a 4,160 volt cable or unit substation problem, so we pulled two technicians away from an acceptance testing project and got them on …