Recent content by cc2

Once I was only 3 metres away (~10 feet) from 400 kV power lines. All the time I could clearly sense the presence of E-field,and that feeling wasn't comfortable at all.Althought I was careful,prepeared and well informed what I was allowed to do,and what not ,I wouldn't do it again! I'm...

Max 30 cm spark was obtained in this experiment.On usual atmospheric pressure max spark lenght depends on voltage and shape of electrodes.The voltage for closing 30 cm wide gap was 150-160 kV .Note this is DC ,but difference between AC 50 Hz and DC air breakdown is small here .That voltage is...

It's at least 1.5 metre from fixed 3 phase 110 kV bus bars.But only in "emergency situations",for trained persons and professionals like HV engineers.That's what I know.For monophase 25 kV railways I dunno. Any references? cherio

ok , thanks. that means the same safety distance holds for everybody in the case of railway. p.s. and OLE is LIVE most of times.

cca 1 Mhz might work ,but only in a pulsed mode-modulated.in this case you should deal only with SURGE impedance of a rail.i don't know how much exactly it is ,but i guess something like 100 ohms.however,the problem with megahertz pulsed is high attenuation of signal ,due to skin effect in...

Hi, Critical zone from live HV cables,from within human or any other grounded object can trigger arcing, can be estimated by the lenght of insulators given HV system.For 25kV@50 Hz railway that would be about 35 cm.But so called 'safety distance' for humans is considerably larger of course.I...

Can you describe the position of the pigon when the arcing occured. I guess somewhere inbetween of live cable and "register arm"- mast ;near or on the top of a cheramic insulator? --- old post above --- --- new post below --- I'm racking my brains out in trying to reconstruct that...

I was also rather surprised to read in that medicine article many of the victims survive 25 kV shock,and thought like you the most of them were dead at spot (burnt to crisp).OTOH,more than 30% victims of the direct lightning strike survive also.So maybe not so strange.. Since you mention "the...

http://www.youtube.com/watch?v=06GzriFiIC0&feature=related In this experiment it was needed 180 000 V to break 30 cm air gap (that's about 1'.And with "poorly" designed/constructed insulator (smooth surface),when such insulator was put between two electrodes the gap strenght was even...

Hi I agree with this part ,and explained why (read on the second page of the forum ,link of which I posted few posts up) ? But it was 25 kV (at least).That's the point.I know that for SURE becouse 750 V can't arc over entire body lenght. O L Leigh posted the list of good questions.We don't...

I agree with me123.:he paid the *price* for what he did. Besides,he is a minor (althought not a child); his age should be taken into account too. But you are missing the point.You see,my only interest in this case is due to the impression I got from various reports :he stood ,with his...

Hi All, Here's the discussion from one of USA forums regarding this accident: Link I guess most of you are from UK ? This is worth investigation ,and I'm sure there are eye witnesses (two friends of that boy).And the latest news are that he is recovering very well (will not need...