Electrical Substations

Substation Testing & Maintenance

Gas Dehydration

Sulfur hexafluoride (SF6) insulates medium- and high-voltage switchgears around the world. In its pure form, this non-toxic, inert gas helps the power transmission & distribution (T&D) industry operate more safely by extinguishing high-temperature arcs. With a much higher...

Breakers & Relays

Utilizing Fault Resistance to Test Distance Relays

Taking power grid protection to an all-new level BY JASON BUNEO & RENE AGUILAR, Megger The testing of distance relays has evolved from testing simple electromechanical relays to the newest modern microprossesor relays. Most modern relays employ advanced algorithms that not only compare the...

Substation Technologies

Extend the Life of Your Circuit Breakers

What to ask to ensure proper circuit breaker testing and maintenance BY ROBERT FOSTER, Megger Protecting a utility’s assets is essential. There are many different apparatus in electrical substations that need to be protected. The circuit breaker (CB) is designed to stop the flow of...

Lightning Protection

Grounding System Maintenance Guide

Grounding systems are a crucially important component of any power supply system, because they directly impact public and employee safety, supply system reliability, power quality and life expectancy of power equipment. In spite of their crucial role in safe, reliable, and economic operation of...

Substation Protection

Protection of Electrical Power Transformers

INTRODUCTIONIn most large electrical systems, generators and power transformers are the two most expensive pieces of equipment. In addition to the capital cost of purchase, these two key devices are also the most critical to continuous and reliable operation of the system.Consider, for example, the...

Physical Security & Monitoring

Animal Mitigation for Electric Utilities

Prevent animal- and bird-caused outages to improve reliability BY MARTY NILES, Cantega Technologies Utilities in North America are under enormous pressure from regulators, customers, and investors to improve reliability performance. Many of the mergers and acquisitions of utilities around North...

Home Transformation Electrical Substations

Vacuum Interrupter Testing for Circuit Breakers

How to predict field life using vacuum interrupters

BY FINLEY LEDBETTER, Group CBS

Utilities have widely replaced older air-magnetic and oil interrupters for circuit breakers rated at one kilovolt (kV) or higher with vacuum interrupters (VI) due to higher interrupt capability. Vacuum interrupters also last up to 10 times the expected lifetime than newer sulfur hexafluoride (SF-6) gas interrupters. Unfortunately, the downside to building a protective device with a long service life is that utility...