Safety in high-voltage substations is the highest priority for all personnel involved, and regulations and laws require all objects to be grounded on both sides before any maintenance work is performed. Failure to ground the circuit breaker (CB) on both sides creates risk of induced high voltages and currents at the ungrounded terminal. Eliminating this risk improves the safety of …
Returning electrical equipment to service after a planned maintenance outage creates a unique set of hazards. Facility managers are under stringent time constraints when taking a system out of service, performing necessary maintenance tasks (as well as making unanticipated repairs), and returning the system to service. Common, real-world factors may place workers at great risk as the system is returned …
A load tap changer (LTC) failure can be catastrophic to the electric power system. The load tap changer (LTC) is one of the few moving parts of a transformer, and this makes it more susceptible to routine wear and tear. When an LTC fails, it may take the transformer with it. Based on our experience, we estimate that about 40 …
Medium-voltage cables are an integral part of modern power systems and have existed for over 100 years in various forms. Over the past 50 years, extruded cables have largely displaced paper insulated cables. Extruded cables offer many advantages over older designs, but are similarly prone to failure. Such failures are a significant impediment to improving overall power system reliability. Since …
With an ever-growing demand for a more reliable distribution grid, utilities are constantly looking for possibilities to optimize their distribution networks by implementing distribution automation. One method to improve the network and reduce permanent outages is using pole-mounted reclosers, due to their wide range of functionality. By introducing built-in voltage sensing on both source and load sides, automation can easily …
Coming up through the ranks in the power industry, I quickly realized I didn’t know what I didn’t know! There are so many facets of the power industry: generation, protection and controls, distribution and delivery, reliability, drives, uninterruptable power supplies, system studies, safety, maintenance, testing, as well as other areas that are vital for the safe and reliable delivery and …
Performing offline electrical tests on transformers can be time consuming, especially when field measurements are not captured correctly the first time. This article identifies the electrical transformer test that technicians often struggle to perform efficiently and correctly and offers three field testing tips to address the issue. Building awareness can help test equipment users avoid situations where a significant amount …
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. Part 1 of this article described the application of various off-line test techniques to assess stator and rotor …
When it comes to electrical systems in industrial and commercial facilities and power plants, total system reliability is the top priority. An approach to electrical system service that encompasses both ac and dc power systems is required. AC and dc systems play an interconnected and equally critical role in ensuring overall reliability, and daily production and equipment protection require seamless …
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 …