Power line Safety label. You may have seen this
label on a commercial antenna or other products. If you did not
read it carefully, take a moment and read it...... carefully. Notice the word "near". Is your antenna too close to those power lines
or could it be? How close is "too close"?
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 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, 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...you can't
see any because of the trees? 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". Whether it is 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, it IS
conductive to high voltage.
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? 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 guys, 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, 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. 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.
Below are a couple of 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 of electricity. Warning...some
portions could be graphic to some viewers! This video was
produced in Canada and some organizations may be different in your
country.
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
