Monitoring a Grounded System

Jeffrey R. Jowett Columns, Spring 2020 Columns, Tech Tips

Electrical faults cause enormous damage due to fires and loss of equipment. But of far greater importance is the danger to human life through electrocution. Ground faults in particular pose the risk of death because a human is generally at ground potential, thereby providing an alternate current path. It takes only about 5 mA to cause a shock, and as …

Troubleshooting

James R. White Columns, Spring 2020 Columns, Tech Quiz

This issue of NETA World covers troubleshooting. A big part of that is being able to interpret a schematic, and some of the most difficult are those for circuit breakers (unless you work in the circuit breaker shop, I suppose). Give these questions a try. Here’s a big call-out to retired Instructor Craig Nelson, who got tired of my hand …

Aligning CT Polarity for Multi-Current Input Differential Relays

Steve Turner Columns, Relay Column, Spring 2020 Columns

Differential relays operate on three or more sets of three-phase current inputs. These relays can be older electromechanical relays with current transformers (CTs) connected in parallel to the three-phase current inputs or newer numerical relays that have more than two sets of three-phase current inputs. Note that it is poor practice to connect CTs in parallel to a single three-phase …

Welcome To POWERTEST 2020

Scott A. Blizard Columns, President's Desk, Spring 2020 Columns

As we leave winter and advance into spring, our industry is preparing for the spring outage season. This time of year, the return of daylight leads to longer work days and more deadlines to meet the expectations of our customers. Be sure to follow the safety policies of your company as well as those required by the facility where the …

Is Troubleshooting Energized Work?

Ron Widup and James (Jim) R. White Columns, NFPA 70E and NETA, Spring 2020 Columns

This issue’s theme brings up a question frequently asked by NETA technicians: “When does troubleshooting end and when does repair begin?” This question is often paired with “What does 70E say about troubleshooting and repair?” We hope to make things clear for everyone in the field. To begin, look at the definition of “working on” (energized electrical conductors and circuit …