ANSI/NETA MTS-2019 Revision Completed ANSI/NETA MTS, Standard for Maintenance Testing Specifications for Electrical Power Equipment and Systems, 2019 Edition, completed an American National Standard revision process in spring 2019. ANSI/NETA MTS-2019 supersedes the 2015 edition, having received ANSI approval as an American National Standard on February 4, 2019. A project intent notification was published in ANSI’s Standards Action …
Obstacles to Measuring Power Transformer Winding Resistance
DC winding resistance is a simple concept that relies on the fundamental application of Ohm’s Law. It is a powerful tool to determine continuity in power transformer winding circuits, specifically connections and tap changer contacts. However, performing a dc winding resistance test presents several technical difficulties that must be overcome: The power transformer’s magnetizing inductance must be removed through saturation …
OMICRON: Driven by Passion and Energy
NETA Corporate Alliance Partners (CAPs) are a group of industry-leading companies that have joined forces with NETA to work together toward a common aim: improving quality, safety, and electrical system reliability. In our CAP Spotlight series, we look at what makes CAPs special and highlight some of their successes. To kick off this issue, NETA World interviewed Wayne Bishop Jr., …
Using Measurement Results to Diagnose the Condition of High-Voltage Rotating Machines—Part 1
Diagnosing the condition of complex systems such as high-voltage rotating machines has never been a simple task. Design requirements, the use of different materials, and demanding operating conditions require multiple off-line tests and on-line monitors to provide information on the machine’s condition. Some tests only yield simple measurement results without high diagnostic value. This article describes the application of various …
How Multi-Function Numerical Protection Relays Use Symmetrical Components
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
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
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
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
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 …
Our Most Important Job Is Working Safely
It was great seeing everyone at Power Test 2019 in Texas! The event went very well, and that’s due to our sponsors, Corporate Alliance Partners, trade show vendors, and most important — the hard work and dedication of the NETA Staff. Mark your calendars for PowerTest 2020 in Chicago February 24 – 28, 2020, and make plans to join us …