Power line Safety label. You may have seen
this label on a commercial antenna or other products. If you did
not take a moment to read it carefully, Notice the
word "near". Is your
antenna "near" those power lines or could it be when
unforseen things happen? How close is "too close"? How
close is "near"?
In this article, we will attempt to inform you
of the EXTREME DANGER posed by installing
an antenna, any antenna, to close to power lines. Now don't make the
mistake and say that can not happen with your antenna, it is
made from fiberglass or other material which is an
insulator!....you may be "dead" wrong! Read
on......
Most new hams are excited when they get their
license and they want to get on the air as soon as possible.
Many of them have not given a thought to the actual installation of
an outside ham antenna and the dangers involved other than
getting it up as high as they can and having it fall on them.
If you don't read any more of this article, then remember
just this very simple statement when putting up any ham antenna,
"If there is a power
line, including the drop line going to your house, over, under or
within a thousand feet of the antenna, IT WILL FALL AND hit your
antenna and YOU while you are installing it! If it does not happen
then...just wait a while...it will fall. If it is under your
antenna, the antenna WILL fall on the power line and you should
not have been so stupid to install it over OR NEAR the power
line in the first place and chances are you are not reading
this. This is how "accidents" happen. This statement is derived by
using "Murphey's Law"...if it can not happen, it will, if
it will happen, it won't..... unless
something else happens......loosely translated for use
with this article! (The thousand feet was a bit of
an exaggeration).
The most important
thing you can do FIRST when installing an antenna is to LOOK before
any part of that antenna, tower, mast or antenna support or any
part of that antenna "system" ever gets off the ground. This
includes the guy wires...what if suddenly one breaks and flys into a
power line. You or someone else is in contact with the mast, or
tries to stop the guy wire.. bang, your dead!
The principle
is very easy. Go outside and consider every possible location for
your antenna. Then look at each possible location with the DANGER
aspect added to it. Where are the nearest power lines? Are you in
the open, or are there trees in the area?
Look behind the
trees or inside the foliage where they might be lurking,
just like a rattle snake hiding there waiting to
"strike". Many times it's the power lines out in plain site that
will get you or one of your helpers or all within it's
reach!
Then, the SECOND thing you need to do is to
get another pair of eyes from a helper to do the same thing...LOOK
again at ALL possible hiding places for the danger of power lines
and remember, it is the power line that you don't see or the one
that you are not tooooo concerned about that will terminate your
fun.
ASSUME THE WORST
WILL HAPPEN!
Now consider that most
guyed antennas like verticals are supported on "something".
It may be a metal mast on the ground, a short metal
"tower" with legs on the roof, or a wooden pole or other supposed
"non-conductive material. Is it conductive to high
voltage? Would you bet your life or your help on not knowing for
sure?
Assume that every thing the antenna is mounted
on AND EVERY THING it is connected to is conductive. Don't
gamble your life on the words, "I think it is
non-conductive"!!!
Assume that the guy wires are
conductive. If one breaks and snaps back or "accidentally"
slips out of yours or a helpers hand, which direction will it likely
go...toward the power line? If it is under much tension at all, it
will act like a whip...Here comes Murphey's Law.... IT
WILL go toward the direction of the power line!
Now,
assume a domino effect. If your vertical falls toward a small tree
that can't take it's weight, the tree will fall, INTO A POWER
LINE....the power line connects to the tree, the tree is connected
to the antenna or a portion of it, and it is connected to
you....that domino effect just bit you like that rattle snake with a
LETHAL BITE!
In short, assume that the antenna or any potion
of it including it's guy wires, feed lines, support, etc WILL fall
or break while you are putting it up "near" power lines. If any
power lines are within "striking" distance of ANY portion of the
antenna or it guys, support ropes, etc.....you may wish...for a
split second, that you had planned your life much better rather than
get in a hurry to DIE!
So far, we have talked about vertical type
antennas. You should apply the above tips to ANY ham radio
antenna, or antenna installation no matter how it is designed,
how small or what it is made of. Your antenna is your "friend"
but it or any part of it could be your
enemy!
Plan far ahead
with these tips:
Let others know what you will be
doing and not just the person or
persons helping you. All of you may need emergency care and no one
may be able to call 911! If you are not sure what
you are doing, get expert help! Plan your
steps as if your life and those around you depend on it.
Notify a family member or neighbor that you will be
putting up the antenna. Ask them to keep an eye AND an ear out for
you... HAVE A PLAN, NOT A FUNERAL!
NO ALCOHOL
OR DRUGS! Alcohol, drugs,electricity and "antenna parties" do
not mix!
Get a good nights rest before the big day.
Have a clear mind when you are installing antennas. Have more
than enough help. Make sure all those involved with the
installation know exactly what will be done and in the proper steps.
Make a plan and let your helpers know ALL of the details... Make
sure all concerned know what to do if the antenna or any part of it
starts to fall toward a power line.....simple....let go....get as far away as possible from ANY
part of the antenna.....let it fall...DO
NOT TRY TO KEEP IT FROM FALLING INTO THE POWER LINE.....YOUR EFFORTS
MAY KILL YOU OR OTHERS!
Do not try to install the antenna in bad
weather with wet ground, snow, ice, etc. There is an old ham
saying, "Bad weather is the best weather to put up an
antenna". Don't believe it. Mother nature loves to disrupt
antenna installations and get you hurt or
.....worse.
NEVER,
NEVER, NEVER put up or even think about putting up any kind of
antenna when you can hear thunder. If you can hear thunder in the
distance, lightning can strike you!
Electricity in Action!
Below are selected videos that may help
you understand the dangers of power lines! (Highspeed connection
required or wait for long downloads)
Like a
Bird on a Wire! This clip taken from
a 2003 documentary, Helicopters in Action. It was shot in IMAX
showing high voltage power line safety from a birdseye view! It
demonstrates some electrical principles in a very close up and
personal way pertaining to personal safety! Fascinating
demonstration of grounding principles, insulation, Faraday
shields, high voltage arching.... and....bravery! Turn your
sound up and watch for the arching.
A Bright
Arc: A Video Guide to Power Line Safety. Produced by WorkSafe
BC Demonstration by professional
linemen about the hazards and results of
electricity. Warning...some
portions could be graphic to some viewers! This video was
produced in Canada and some methods shown may be different
in your country.
WARNING! VERY VERY GRAPHIC
VIDEO LINK FOLLOWS!
It is too graphic to
be shown here! This video on YouTube
shows 4 painters who were electrocuted while moving a portable
metal scaffold that touched overhead power lines. They never
looked up! Video From
YouTube here. You will
be asked to sign in and verify your age before viewing this horrible
video! Come back here when you've had enough of this awful
incident!
+++++++++++++++++++++++++++++++ Read
some very interesting follow up comments pertaining to
power line accidents recently making the news.
This used with
permission from Chuck, K0XM "I just saw this one on the
news, and had to write a bit for you guys to pass on to the ham
community, especially the newer hams.
Please forward this in
its entirety, as I am using my professional back ground to back
up my
statements.
<><><><><><><><><><><><><><>
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 years as a
substation 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 MINIMUM 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 substation that AUTOMATICALLY closes the
feeder 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 substation end, the protective device
is set for the full fault capabilities 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 multiples 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
possibility 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,
K0XM
Well, there you have it. Hopefully some
or all of the material above will help at least one of you save your
life or others. Pass this link along and get the word out...be
safe...have an "antenna party", not a FUNERAL........enjoy ham
radio....73, Don N4UJW Hamuniverse.com
