[SEDXC] KC Ham Electrocuted

k4hb k4hb at yahoo.com
Mon Jul 14 10:21:16 EDT 2008


Sad news from the Kansas City DX Club. The message 
from KØXM is the best I've ever seen about the dangers of power lines. Here you 
have expertise in ham radio and high voltage power lines from one source. This 
is something important to pass along to newcomers, as well those who have been 
around for a while. I know of two CBers in my area who were killed putting up 
"fiberglass" verticals. Gotta remember, If they were just fiberglass they 
wouldn't radiate RF.
 
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KCØTIG and his son were electrocuted today while trying to put up an 
antenna.
 
http://www.myfoxkc.com/myfox/pages/Home/Detail?contentId=6973013&version=5&locale=EN-US&layoutCode=VSTY&pageId=1.1.1


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THIS NEWS ITEMS MOTIVATED CHUCK KRALY, KØXM, TO 
WRITE THIS MESSAGE:
 
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I just saw this one on the news, and had to write a 
this message to be passed on to the ham community, especially the 
newer
hams.
 
We lost another ham today, and it is a very sad 
event. The parties  involved, were installing a Comet FIBERGLASS 
antenna,
that came in contact with a single 7620V power line. Now how do I 
know what the exact voltage is? I built and maintained the substation that fed 
this circuit. I spent 27 yrears as a substaion technician for the Board of 
Public Utilities. I am still in this field. So, I feel I have some experience in 
what I am passing along.
 
In a nutshell, the location of the accident was a 
few blocks from the substation. The wires you see going thru the residential 
areas are AT MINUMUM 7200 volts from each wire to ground, and between any two 
of  them is 13,800 volts. This is nothing to play with at any time. I have seen 
a fault TOTALLY vaporize 1" copper buss (which is solid). Imagine 
what it 
can do to a human.
 
Each wire is fed from what is called a 3 phase 
line. From there, it can be broken off and sent down a property line as 
a
single wire. Those are called "laterals" Yes, you will see a device at the 
break out point, and this is a fuse. BUT the caution needs to be conveyed. These 
fuses are in the 60-100 amp range. This is at 7200 volts. On top of that, 
anytime a tree falls across a line, or a pole gets hit, there is a circuit on 
the "feeder" at the substaion that AUTOMATICALLY closes the fedder back in, and 
TRIES to restore the power to the area. Some of these "reclosers" can operate 
2-5 times, depending on how they  are set. Now from the substaion end, the 
protective device is set for  the full fault capabilites of the line. In the 
case of
BPU, this can  be set at 600 AMPS, and multiples of that value. The 
protective devices are set for what is called a "time"
or and "instantaneous" 
operation. Picture a fast blow fuse and a slow blow, and you will understand the 
difference in the settings. These setting are at multiple of the 600 amp value. 
So, if there is a direct short, then it  will not trip until it reaches a value 
at, oh lets say, 8 times that value. So we are looking at 4800 amps. and this is 
at 7200 volts and  lower. So, it trips, then it energizes it AGAIN. The 
possiblity of survival is slim and none.
 
Now remember how I said they were installing a 
FIBERGLASS antenna? Well guess what. It is metal inside. Yes, fiberglass
does 
not radiate as we all know. Hence the metal. That is what caused the accident. 
They got too close to the line (remember your 'magnetic lines of flux' theory? 
If not, look it up on the web). There is a minimum approach  area that MUST be 
followed. This changes for ALL voltages. This distance must NOT be broken. If it 
is a flashover will happen, and it  is not pretty. Electricity will find the 
shortest path to ground. In this case it was a couple of men.
 
Folks, this is nothing to take chances with. In my 
almost 30 yrs as a ham, and 27 yrs in the power utility field, I have seen way 
too many "accidents." Stop, look and if it is close or SEEMS that way- DON'T. 
Find another place. High voltage lines are NOT forgiving. Your life depends on 
it. You always hear "it is the amps not the volts" well I can tell you when you 
get at these levels, who is going to argue what killed the person who had the 
accident. PLEASE ,PLEASE follow the warnings.
ANYWHERE close is too 
close.
 
Stay safe, and I hope we can enjoy many more years of 
hamming.
 
Thanks Guys,
Chuck Kraly, 
KØXM

______________________________________________
Kansas 
City DX Club
Does anyone read this stuff?
KCDXC mailing list
KCDXC at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/kcdxc
 
 
 
 
73, Hal K4HB
http://www.k4hb.com
http://www.Hi-TechRedneck.com
http://www.k4hb.com/postage.html
     
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