Ground Faults in Photovoltaic Systems

Jeffrey R. Jowett, Megger Columns, Spring 2022 Columns, Tech Tips

Solar farms, which are exposed to the elements, are especially at risk for failure and require dedicated electrical maintenance. Good grounding is essential, as the panels produce high DC voltages that can be sources of shock and fire, as well as induced voltages and electromagnetic interference on lines. With respect to grounding, there are two types of photovoltaic (PV) systems: …

Arc-Flash Reduction Techniques

Virginia Balitski, Magna IV Engineering Columns, Spring 2022 Columns, Tech Quiz

As NETA Certified Technicians, many of the tests and inspections performed may expose workers to electrical hazards. ANSI/NETA MTS, Standard for Maintenance Testing Specifications for Electrical Power Equipment & Systems specifies that individuals performing these tests shall be qualified and capable of conducting the tests in a safe manner and with complete knowledge of the hazards involved. One of these …

Vehicle Safety for the Workforce

Paul Chamberlain, American Electrical Testing Co., LLC Columns, Safety Corner, Spring 2022 Columns

Commuting to and from work by vehicle is a daily routine for many. The COVID pandemic has changed how some organizations operate, forcing many employees to work remotely, but for those who need to be on the job doing physical work, the commute never stopped. For some, driving to a jobsite, client sites, the shop, the parts supplier, and everything …

The Three Arc-Flash Mitigation Levers

Mose Ramieh Jr, CBS Field Services Columns, In the Field, Spring 2022 Columns

“It’s faster for us to put on the 40-calorie suit to rack breakers out than it is to use the remote racking system,” the customer said — and I wanted to add, “Yes, the remote racking system bought for your safety at a significant investment from your company.” But I did my best to hide my dismay and took the …

Generator Stator Ground Fault Protection

Steve Turner, Arizona Public Service Company Columns, Relay Column, Spring 2022 Columns

Generator faults are usually serious and can lead to significant repair costs and long outage times. PART I: ANALYSIS Part 1 demonstrates how to analyze a stator ground fault for a large combustion turbine generator. The faulted phase and fault location are determined using fault voltage recorded by the numerical generator protection relay installed for this generator. This information is …

Fault on Feeder M1A: Guidance from NFPA 70E — Part 3

Ron Widup, Shermco Industries Columns, NFPA 70E and NETA, Spring 2022 Columns

This is the last in a three-part series of articles as we navigate a 15 kV feeder fault and the subsequent repairs. We have discussed how NFPA 70E is an important tool for the electrical worker to use in the field as they troubleshoot, repair, and restore electrical equipment after a significant fault event, all with an eye on getting the …

Arc-Flash Hazard and Mitigation

Eric Beckman, National Field Services, NETA President Columns, President's Desk, Spring 2022 Columns

First, welcome to Denver and PowerTest 2022. It certainly is nice to be back to an in-person event! This year also happens to be NETA’s 50th anniversary. Be sure to watch out for special events celebrating this anniversary. You won’t want to miss them. There has been so much development in the area of arc-flash hazard awareness and mitigation in …

Hand Protection

Paul Chamberlain, American Electrical Testing Co., LLC Columns, Safety Corner, Winter 2021 Columns

Workers’ hands are the most commonly injured body part. Whether the hazard comes from rotating machinery, pinches between two materials, heat, chemicals, or electricity, your hands are under constant attack. Without them, every task would be difficult to perform. This article identifies the common hazards and risks to a worker’s hands as well as ways to mitigate injuries and promote …

MCC Catastrophic Failure at a Client Facility

Adam Murray, Advanced Electrical Services Ltd. Columns, In the Field, Winter 2021 Columns

AES personnel were dispatched to a gas plant in northern Alberta, Canada, for emergency repair of a failed 600 v MCC bus. Before the technicians arrived, the 600 v bus components had already been disassembled by facility personnel to prepare for installation of a new MCC section. For our client, getting the facility back up and running was more critical than …

Analysis of Generator Protection Operations

Steve Turner, Arizona Public Service Company Columns, Relay Column, Winter 2021 Columns

This article analyzes several protection operations for large combustion turbine generators. Generator protection trips tend to be rare, so any major event is always of interest. EVENT 1: CLOSE-IN THREE-PHASE FAULT A large gas combustion turbine generator experienced a close-in three-phase fault during a rainstorm. The generator terminal voltage is rated 13.8 kV line-to-line, and the machine is high-impedance grounded. The …