“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 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 …
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 …
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 …
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 …
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 …
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 …
Previously, we discussed a 15 kV feeder fault at a manufacturing plant and how NFPA 70E is an important tool for the electrical worker to use in the field as they troubleshoot, repair, and restore the equipment to get the facility up and running. To recap, here’s what happened: The main circuit breaker in one of the plant’s three medium-voltage substations …
NETA has been setting standards that pave the way for the minimum requirements to ensure an electrical system operates reliably and safely since 1972. As a result of several widespread blackouts compromising the electric grid, the North American Electric Reliability Council (NERC)was appointed in 2006 by the Federal Energy Regulatory Commission (FERC) to develop various standards to aid in the …
In an actual reported case, a severe storm blew down a large tree that struck a residence. A meter that should have been reporting 240 V reported a phase-phase voltage of 124 V. The falling tree had pulled down the service, which had then been re-attached by a service crew. A routine voltmeter check revealed 118 V between the left hot leg and neutral, …