By Carl R. Tamm
If your concept of corona is that it is commonly consumed with a slice of lime, you might wish to read a bit more about issues in our industry that differ slightly from that concept!
Fair weather radio and television interference (RIV and TVI) generated by overhead lines are most frequently caused by corona. Corona results from voltage overstress on the surfaces of conductors and other energized components. On distribution lines, sparking at lightly loaded connections and associated non-conductive films may also generate RIV/TVI. Corona also results in resistive power loss on transmission and distribution lines. Under foul weather conditions virtually all energized conductors and components are in corona.
With all this concern about Corona and at the request of a few customers we recently conducted RIV and Corona tests on CSF-1108-024-COR345 and CSF-1302-024-COR500 standard production ClampStar® units.
The tests were conducted in the HPS (Ohio Brass Company) high voltage environmental test chamber in Wadsworth, OH on September 13, 2012. The RIV tests were conducted in accordance with NEMA 107, “methods of measurement of radio influence voltage (RIV) of high-voltage apparatus”. Corona observations in complete darkness were made with the aid of a Noctron V night vision system (night image intensifier) S/N 5046. Click here to get the full report.