Lau, Gary wrote:
Suspect it's urban myth. I ran a "skunk zapper" electric fence for several years which was powered by a 9 kV, 60 ma NST. Because of the capacitance of the fence wires the terminal voltage was a bit above 9000. Day and night, rain [when it rained here in Socal as it never does now] and shine. Still in good shape. This is one which had experienced a short at one end [accidently opened up the main gap when I wasn't using a safety gap] which I removed by heating the tar around shorted end with a hot air gun until it was melted below the level of the screw through the insulator.Changing the subject line... Yes - I too have heard many times that running an NST with no load will stress its insulation beyond what it was designed for. But it does seem unlikely that an NST should be designed to self-destruct should its connection to the load fail. So being the skeptic that I am, I have to wonder about the origin of that belief. Did it come from a source in the sign or transformer industry, or just a coiler who observed that an in-use NST with a sign operates at well below its faceplate voltage? Gary Lau MA, USA
Of course, "your experience may vary". Ed _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla