INSTALLING GROUND RODS INSIDE BASEMENTS

[packrat]

Yupp and its one of those damned if I do damned if I dont type deals and as I tell people if you take a direct hit there isnt alot your gonna do about it anyway and its just natuire of the beast

Tony,

You hit it right on the head. If you are gonna take a hit, there is not a damn thing that will stop it. That is why my antenna connections go out the window in bad weather. Better safe.

PR

 

[IRock817]

Now just from a layman that knows enough about electricity too stay away from it! I have bonded all my junk too help with rf feedback, static, and all the other varmints that plaque our hobby. When it storms all my stuff gets disconnected, even the ground from shack to ground rod. If you get a strike, I don't think a two inch thick cable to ground your stuff will stop the smoke! Just my thoughts thou!

 

[Lefty]

Drill and pound at an angle.

Sounds like my first date!

 

[Captain Kilowatt]

CK,

I highly respect your opinion, but I am going to play devils advocate here.
Convince me.

After 40 years( many in FLA, the lightening capitol of the world) with NO problems, what am I doing wrong?

There is a difference between not doing something right and doing something wrong. The difference is in the actual "doing" part. You did not do something wrong but you did not do it right either.

Every house and barn in the country used to have lightening rods. most do not now. Has there been a catastorphic increase in the number of houses burned due to lightening strikes since this phenomenon?

Most lightning rod and ground systems were never installed properly in the first place. A lot were sold by shady salesmen during a big fad decades ago. The likelyhood of being struck by lightning is not dependent on the presence of lightning rods or not. It is simply chance and chance plays no favours.

ARRL even states that if you can not run a short, direct ground, dont run one at all. (Do not put a shack on an upper floor.) Long grounds can cause more problems than they solve. So if no ground is better than a long ground path, why is a ground path needed at all??? (Hint: It was much more important years ago with the old tube equipment that used to bite its owners pretty regularly)

I prefer to get my electrical safety info from professionals and definitely NOT the ARRL. As for the tube gear, we are talking about a safety ground and not a lightning ground. Also, how do you suppose they ground all those broadcast transmitters in buildings like the Empire State building?

Also, are we talking rf ground or safety ground?

Neither. I am talking about a lightning ground which is different from either an RF ground or a safety ground. A safety ground is taken care of by the third wire in your house wiring and is connected back to the AC entrance panel.

I have an electrical background and do understand these things, but I also understand the laws of physics state that an ungrounded item will not conduct electrical energy. It needs a complete path, so why give it a complete path? Most of the electrical codes are there to keep morons who stick their fonger into electrical sockets and rewire the christmas tree lights incorrectly safe from themselves. How many homes are still out there with two wire systems? (MANY MANY of them) Are the occupants dying with alarming regularity because of this? NO!

Whether something will conduct electricity is a function of the applied voltage. Given enough voltage even a normal insulator can break down and conduct. Ever hear of a house roof or barn roof being struck by lightning? Ever hear of a tree being hit by lightning? What happens in those cases when the only path for lightning is whatever path breaks down under the extremely high voltages presented to it? Usually a hole gets blown in the roof and the building catches on fire and in the case of a tree it usually gets split from the moisture turning to steam due to the heat. What we consider an insulator at 12 volts, 120 volts or even 1000 volts may not be and usually is not an insulator at millions of volts as is present in a lightning strike.

Anyway, have fun.op:

PR

Tony,

You hit it right on the head. If you are gonna take a hit, there is not a damn thing that will stop it. That is why my antenna connections go out the window in bad weather. Better safe.

PR

Properly done you do not even have to disconnect your coax cable and you can survive a strike unscathed. Broadcast stations do it all the time. Look at Tom, W8JI's site here ans see what he does and what he has to protect.

http://www.w8ji.com/ground_systems.htm

You didn't say you throw the coax out the window previously unless I missed it. That removes the path from the antenna through the cable to the radio and onward to the house ground. Lightning traveling that path is what does the destruction. By doing so you have just put yourself on the same playing field as any other house on the block without an antenna basically. Commercial installations have the transmission lines connected 24/7 and install extensive ground systems to offer an alternate path in the event of a strike. They cannot just throw the cable out the window and function. If you can then great, but most hams and CB'ers cannot or do not for various reasons and those people MUST be aware of what can and will happen when that lightning has no other path to ground than a piece of coax cable laying open ended on the floor. It may be an insulator at 1000 volts but I guarantee it is not at a million volts or more.

 

[sanman]

NOW THE BIG QUESTION ? IS IT SAFE TO PUT GROUND RODS INSIDE THE HOUSE ??? IF I DO GET HIT WITH LIGHTING , CAN IT START A FIRE SINCE A 4 GAUGE STRANDED WIRE MIGHT FRY UP . THE WAY IM READING THE POSTS HERE SOUNDS LIKE ALOT OF VOLTAGE IS BEING PRODUCED . DOES DRY GROUND ATTRACT ITS PATH QUICKER ? DUE TO THE FACT THERE'S NO MOISTURE . THIS MITE SOUND STUPID BUT HAVING LITTLE KNOWLEDGE ABOUT THE FUNCTION OF ELECTRICAL THEORY'S. THE POST GIVES ME SOME IDEAL BUT I GET LOST IN ITS PATH. IVE HEARD OF ARTIFICIAL GROUND BUT THATS OUT OF THE QUESTION , FOR THE SHACK. IS ARTIFICIAL GROUND ONLY FOR RF NOT SAFETY ?

 

[Robb]

Let's recap a few things about lightning and your station:

1) It strikes where the largest potential voltage between the largest Earth ('ground field') voltage exists and where the largest voltage in the storm cell occurs - overcoming even great surface resistance to discharge - to the least path of resistance. Trees, houses, antennas, and occasionally people too. Nothing is exempt. Yup-yup.

2) It is best to have an low impedance flow to lightning already in place. This is where the lightning would flow anyway. All you are doing is providing a path that has the least possible resistance so that it will flow there, and not into your house. The lightning ground should be outside the building. It should be put together well enough to endure many future strikes and not break down.

3) It isn't an expensive project. Probably less than $200 for the homeowner. But it needs to be done correctly to be effective.

4) if the strike takes a path of higher resistance (tree, barn, or your coax); then these items will heat up, burn, or even explode.

5) Remember 'Murphy's Law'? If you live in an area prone for lightning strikes; then your home may well get struck eventually. If you have a ground system in place and it isn't done correctly; then the lightning will find the least path of resistance for you.

Here is a FAQ:

http://www.ipclp.com/print/aud_ho_faq.html

 

[Captain Kilowatt]

Let's recap a few things about lightning and your station:

1) Its strikes where the largest potential voltage between the largest Earth ('ground field') voltage exists and where the largest voltage in the storm cell occurs - overcoming even great surface resistance to discharge - to the least path of resistance. Trees, houses, antennas, and occasionally people too. Nothing is exempt. Yup-yup.

2) It is best to have an low impedance flow to lightning already in place. This is where the lightning would flow anyway. All you are doing is providing a path that has the least possible resistance so that it will flow there, and not into your house. The lightning ground should be outside the building. It should be put together well enough to endure many future strikes and not break down.

3) It isn't an expensive project. Probably less than $200 for the homeowner. But it needs to be done correctly to be effective.

4) if the strike takes a path of higher resistance (tree, barn, or your coax); then these items will heat up, burn, or even explode.

5) Remember 'Murphy's Law'? If you live in an area prone for lightning strikes; then your home may well get struck eventually. If you have a ground system in place and it isn't done correctly; then the lightning will find the least path of resistance for you.

Here is a FAQ:

Lightning protection for your home

Yup, yuuupp, and yuuuuuppp!!

 

[sanman]

THANK U GENTLEMEN ! SO MANY OBSTACLES ! i LIVE IN NEW YORK CITY, OUTER BOROS, WERE HOUSES ARE ONLY A COUPLE FEET AWAY.WEATHER HERE IS UNPREDICTABLE ,COLD ONE DAY WARM THE NEXT. RAINS OR IT SNOWS . WINDS ARE HARD OR SOFT. MOTHER NATURE FARTS THE WRONG WAY AND YOUR SCREWED, ETC, ETC . WE GET LIGHTING HERE ON AND OFF , IN ALL 4 SEASONS . HOUSES AROUND ME HAVE TV ANTENNAS ALL OVER THE PLACE . LARGE OR SMALL. NONE OF THEM ARE GROUNDED. NEVER SEE THEM GET HIT. AMAZING SINCE I SEE LIGHTNING COME TO GROUND. MY PROBLEM IS LOCATION FOR GROUND RODS . WHAT I HAVE TO DO IS TAKE PICTURES OR VIDEO OF MY SURROUNDINGS .I HOPE SOMEONE COULD BRAINSTORM A IDEA FOR HELP. FOR ME TO DO THIS IS THE SAME TO POST DOCUMENTS . IM NEW TO THIS. THANKS

 

[sanman]

SAW THE SPACE SHUTTLE FLY BY MY HOUSE . IT WAS SPECTACULAR! I LIVE NEAR KENNEDY AIRPORT

 

[Captain Kilowatt]

NOW THE BIG QUESTION ? IS IT SAFE TO PUT GROUND RODS INSIDE THE HOUSE ??? IF I DO GET HIT WITH LIGHTING , CAN IT START A FIRE SINCE A 4 GAUGE STRANDED WIRE MIGHT FRY UP . THE WAY IM READING THE POSTS HERE SOUNDS LIKE ALOT OF VOLTAGE IS BEING PRODUCED . DOES DRY GROUND ATTRACT ITS PATH QUICKER ? DUE TO THE FACT THERE'S NO MOISTURE . THIS MITE SOUND STUPID BUT HAVING LITTLE KNOWLEDGE ABOUT THE FUNCTION OF ELECTRICAL THEORY'S. THE POST GIVES ME SOME IDEAL BUT I GET LOST IN ITS PATH. IVE HEARD OF ARTIFICIAL GROUND BUT THATS OUT OF THE QUESTION , FOR THE SHACK. IS ARTIFICIAL GROUND ONLY FOR RF NOT SAFETY ?

First off an artificial ground is simply a tuned wire that is meant to act as an RF ground in situations where there is interference from the transmitter or where a good SWR cannot be obtained due to the type of antenna and feed being used. It is NOT a safety nor a lightning ground in any way, shape, or form.
Ideally you do not want to bring that strike energy into the house and even a ground rod placed outside near the foundation is a better place to put it. Even if you had to drill a hole in the concrete or asphalt and then drive the rod it is better.I would only install a ground rod inside if it was the last resort and no other way was possible and then I would make the length of ground cable as short as possible as it should be that way anyway. I just do not know what would happen to a concrete floor that had all that energy dissipate underneath it. It may be fine or it may crack or even violently blow apart depending on the moisture present and the energy involved.

As for the 4 gauge wire, not to worry about it burning up. It is a bit larger than the minimum recommended by the NEC (National Electric Code).

THANK U GENTLEMEN ! SO MANY OBSTACLES ! i LIVE IN NEW YORK CITY, OUTER BOROS, WERE HOUSES ARE ONLY A COUPLE FEET AWAY.WEATHER HERE IS UNPREDICTABLE ,COLD ONE DAY WARM THE NEXT. RAINS OR IT SNOWS . WINDS ARE HARD OR SOFT. MOTHER NATURE FARTS THE WRONG WAY AND YOUR SCREWED, ETC, ETC . WE GET LIGHTING HERE ON AND OFF , IN ALL 4 SEASONS . HOUSES AROUND ME HAVE TV ANTENNAS ALL OVER THE PLACE . LARGE OR SMALL. NONE OF THEM ARE GROUNDED. NEVER SEE THEM GET HIT. AMAZING SINCE I SEE LIGHTNING COME TO GROUND. MY PROBLEM IS LOCATION FOR GROUND RODS . WHAT I HAVE TO DO IS TAKE PICTURES OR VIDEO OF MY SURROUNDINGS .I HOPE SOMEONE COULD BRAINSTORM A IDEA FOR HELP. FOR ME TO DO THIS IS THE SAME TO POST DOCUMENTS . IM NEW TO THIS. THANKS

I have the same conditions here as you do. I can have thunder and lightning any month although during the winter it does occur rarely. As I have said over and over, whether an antenna structure does or does not have a ground on it has no bearing whatsoever as to the chance of it being hit by lightning. My old 40 foot tower is well grounded and stands about 20 feet to the rear of my house. The power lines run in front of the house about 120 feet away. A couple years ago I was in the yard looking at a very disturbed looking sky. The light had a weird look to it and I knew we were going to be in for a big storm and could hear thunder off in the distance. I walked around to the front of the house to see the sky better and as I rounded the corner and stood in the middle of the lawn out of nowhere !!BOOM!!. All I saw was a purplish white flash and there was an ear splitting crack so loud it nearly knocked me down. It scared the hell out me. Lightning struck the power lines in front of the house. They are about the same height as my tower or maybe a bit lower and certainly had a poorer ground due to the length of cable involved. Why did it hit the power line instead of my tower? Because that was where the difference in voltages was the greatest at the time. Grounding of my tower had nothing to do with it but had it hit the tower instead the ground would have been able to take the brunt of the energy.

Oh yeah, I only lost a DVD player as a result of that hit to the power lines.

 

[sanman]

THANK U KC ; U DEFINITELY PUT THAT POST IN LAYMEN TERMS THAT I CAN UNDERSTAND ! THANK GOD U SURVIVED THAT ONE , MUST OF BEEN A WEIRD EXPERIENCE TO FEEL THAT ONE . MY POWERLINES ARE UNDERGROUND , LUCKY FOR ME , LAST YEAR WITH ALOT OF THE RAIN WE HAD, BLEW OFF THE THE TOPS . NO ONE GOT HURT. I KNOW ITS BEEN SAID SHORTEST TO GROUND, BUT IS THERE ANY LENGTH TO HOW SHORT? DOES WAVELENGTH HAVE EFFECT TO DISTANCE FOR GROUNDING? EX: 3FT. , 6FT. , 9FT.

 

[ahamoperator]

I won't argue theory here with anyone, but can tell you I used to believe in the
"no-grounding thing". About 27 yrs ago , just a year before my first ham
license I was a CB op. The local guys always used to say " take your coax off
and put the end in a big jar" sounds silly does'nt it?

Anyway I put my coax end in a jar...hi... One night we had a lightning strike
on the Penetrator 500. Lightning jumped from inside the jar to the rig that
was still plugged in, and spot welded the case together and ruined another
CB radio that was next to it.

Anyway after that I started believing in an alternate-path type grounding
system.

Sometime in 1999, we had our second antenna strike, the shack was in the
Master Bedroom, Imagine being awoke in the middle of the night by a shower
of radio parts on the bed. I had not unhooked anything, and had been doing
some moving around of the rigs, and did not have them grounded other than
through the power supplies. My main HF was fixable, though the 3 month old
satellite rig was burned beyond repair. The strike entered (or exited) through
a 2 meter antenna.

Since then the ground system is always in place, and I unhook all coaxial
cables and hook them to a proper ground, while unplugging all power supplies
and amplifiers...



For whatever its worth...73, Keith

 

[Mudfoot]

Sounds like my first date!

I think I may have met her sister.

 

[Mudfoot]

I have never had any issues with lightning (knock on wood ) since I've been on the air. I don't know of anyone "personally" having any shack strikes.

I do remember being at my grandma"s house when I was 10 or so. Lighting hit the TV antenna. The twin lead came in above the chimmny, down the wall and long the floor about 16 ft. to the TV. It was like Detcord flashing the entire length towards the TV. Lit and smoked the TV, and cought the attic on fire.

Scared the hell outta me. I try to ground as best I can now.

I would like to see a collection of "Shack" lightning damage. Should be a bunch on the net.

 

[Robb]

Sometimes the strike can do damage subtly. Local friend was talking to me/TXing on his Icom 756 Pro II when a strike came down less than an 1/8 of a mile away (happened just last year). I didn't hear him for another fifteen minutes or so. He had to hook up a backup rig and then tell me that the strike took out the Icom. Sent it to a shop and and they confirmed the damage to the PA section. Lightning is rare but not too rare around here.

Was about to go on a date back in the late 80's one early evening. We had to stay inside my apartment and wait because we had a real freak of a storm that hit us one day in Spring. We decided to watch some TV and let the storm pass first. All of a sudden there way a real bright flash in the room and the TV (only a month old or two) quit and then it smoked a little. We didn't hear the boom; but she did let out a real quick piercing shriek and jumped 2-3 feet in the air when the room flashed. Got word a week later from the power company that a pole was struck nearby. I didn't hear any thunder boom/crack though.