Conventional testing of medium- and high-voltage circuit breakers (MV/HV CBs) involves measuring the timing and travel of the main contacts and their corresponding resistors (pre- or post-insertion) if any, along with the current profile of the operating coils, and occasionally the timing of auxiliary contacts. This article explains several techniques available to improve or extend the scope of testing. Aspects …

Did you know that the most common characterization of a ground rod may not work for lightning? In 1997, an experiment at the International Center for Lightning Research and Testing (ICLRT) at Camp Blanding, Florida, challenged the predominant view that ground rods are essentially resistive. That experiment found that the waveshapes of lightning currents in a building grounding system and those entering the electrical …

Electrical safety is often described as a three-legged stool encompassing proper installation, routine maintenance, and applicable safe work practices. It is this relationship that sets the stage for what can best be described as the electrical safety ecosystem as it lives within the larger overall NFPA Fire & Life Safety Ecosystem™. This Ecosystem is made up of eight key elements …