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! When the topic of low-voltage circuit breakers comes up, what are …
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 …
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 …
Multi-function numerical generator protection relays can calculate the insulation resistance of a synchronous generator field winding to ground. The calculation can be performed on an energized or de-energized generator. The particular relay discussed in this article uses a separate module located close to the rotor slip rings and brushes to monitor the field. The close proximity of the module to …
This issue of NETA World continues with the deep dive into the NFPA 70E revisions that went into the 2021 edition. Part 1 in the Winter 2020 issue covered the reorganization (which was not nearly as extensive as in previous editions); reviewed Article 100 Definitions; and began on Article 110 General Requirements for Electrical Safety-Related Work Practices with Section 110.1 …
It is January 20, 2021, and the country is in the midst of a resurgence of the COVID-19 virus. The Conference Committee, in consultation with the NETA Board of Directors, has decided to go totally virtual with PowerTest 2021, the premier electrical maintenance and safety conference intended for all electrical professionals and especially beneficial for field service technicians, inspectors, utility …
Circuit breakers used in low-voltage applications include air circuit breakers, insulated-case and molded-case circuit breakers, and miniature circuit breakers. Air circuit breakers or low-voltage power circuit breakers typically function as the incoming device on a low-voltage switchboard. In the event of an overload condition or short circuit, current sensors in low-voltage power circuit breakers measure high currents and send the …
Low-voltage circuit breakers are predominant in virtually every electrical power system. A 2008 NETA survey and associated IEEE paper showed that 22% of these breakers did not follow their time-current characteristics, and 10.5% did not operate at all when service-aged maintenance was undertaken. The majority of failures were mechanical in nature; this indicates regular maintenance must be a priority. Low-voltage …
Circuit breakers come in several types of operating styles differentiated by what they use to safely extinguish an arc in a circuit, including air, air-magnetic, vacuum, and SF6. While most older circuit breakers were manufactured in the United States, mostly by companies such as Westinghouse Electric, General Electric, and Federal Pacific, today many circuit breakers are imported. Older companies merged …
QP Testing is located in the Chicagoland area and provides electrical testing and field services to the utility, industrial, and commercial markets. Our NETA Accredited Technicians and Engineers are experts in testing, analysis, and maintenance of our customers’ electrical power systems, including primary and secondary injection testing of circuit breakers, transformer testing, relay calibration, cable testing, preventive maintenance, and outage …