Detecting Circulating Currents and Hot Spots in Normally Non-current Carrying Conductors and Structural Members

Often normally non-current carrying conductors, conduits, or even structural members contain circulating currents that are induced by currents flowing in adjacent conductors such as cable or bus. There is usually no way to measure the magnitude of these currents, and sometimes it is difficult to even detect electrically that they are there. The question might arise, why worry about these currents? The answer is heat. As with any current flow, these circulating currents produce heat when they flow across a resistance. In extreme cases there might be enough heat to cause equipment damage or even fire. Conducted or radiated heat from nearby hidden sources can also cause hotspots in unexpected locations. This heat is easily detected with infrared scanning. Through its Comprehensive Services Program (CSP), the Tennessee Valley Authority contracts with its distributors of electric power to provide a variety of services to the distributors and their customers. One of these services is infrared scanning.