Another grounding question - Please Help!

[fredg]

I hope I don't get in trouble with the mods for starting a new thread but I really need to get an opinion on this!

OK, in my other threads I wrote about how I am grounding my outside antenna. I sunk a 8' ground rod and used 6 awg solid copper wire to connect the ground rod to my mast.

My next project it to bond this rod to my main house ground. I searched and searched and cannot find a ground rod for the house.

I did figure something out and thus my question....

I have a tiny basement that only contains my furnace and and water heater. There is a 240 breaker panel also in the basement. This is for the air conditioner and dryer.

I opened up the panel to try and see if there were any clues as to a ground.

It has a heavy bare twisted wire that I figured is the ground for this panel. The wire comes out of the box and disappears to an area that is un-accessible.

I remember reading that a lot of old houses used water pipes for grounds.

So I took my VOM and checked between the ground wire in the 240 panel and a water pipe running through the basement.... sure enough they are connected!!!

So I have identified my ground. As a side note like I said in my other post all but about 2 outlets in my house are not grounded even though they have 3 prong outlets (bad I know).

So the obvious question is can I bond my new ground rod to the water pipe in the basement or to the ground connection in the 240 panel?

EDIT TO ADD: I ran a temporary wire from the water spigot on the side of my house (and about 15 feet from my ground rod) to the 240 panel ground in my basement, used my VOM to check.... sure enough they are connected. Seems like I should be able to connect my ground rod to the spigot. Heck this might give the overall house a better ground. Opinions?

 

[LtDoc]

Depending on the age of the house and the requirements of your local area, the primary power box should be grounded and NOT just to the water pipes. If it's not then I would definitely NOT tell your insurance company or city inspectors.
The 'ground' you are dealing with is a safety ground, usually nothing to do with RF, big difference. Doing a good safety ground isn't simple (or cheap if you are doing it 'after the fact').
Good luck.
- 'Doc

 

[ka3jjz]

Get a professional help from a local electrician. Don't skimp on the details here. As Doc stated in his message, there are different types of 'grounds' - and fooling around with 240 is not something to be done lightly

Mike

 

[fredg]

Get a professional help from a local electrician. Don't skimp on the details here. As Doc stated in his message, there are different types of 'grounds' - and fooling around with 240 is not something to be done lightly

Mike

I only went into the 240 box to check and see if the ground in there was connected to the water pipes. I also decided I want nothing to do with that box!

It is quite a mystery as to how this house is grounded. My only guess is that as the back of the house where the main panel is and is on a cement slab maybe they put a ground rod in the slab when building the addition. Then tied that into the water pipes but when viewing from the basement I can see pretty much all the pipes including where it comes into the house and I do not see any ground wires attached.

I have had this antenna up for at least 15 years now without a ground, I am tempted to just unhook my new ground rod and forget about it!

EDIT TO ADD: So my next question is, SHOULD I leave the antenna attached to the ground rod since I am NOT going to bond the rod into my unknown house ground or should I just go back to no ground?

This site Antenna Basics says this (see the website for context):

This 6-gauge wire, shown in red, connects the new ground rod to the breaker box (typically). This wire will help absorb the lower frequency components of a direct strike. If this seems like too much work for too little benefit, don’t be discouraged from at least installing the ground rod.

 

[w2xq]

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Our house ground is outside, under the exterior electric utility power meter and the connection to the street. Just a thought. FWIW, I also wouldn't muck around in the interior circuit breaker box, but that's me.

 

[fredg]

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Our house ground is outside, under the exterior electric utility power meter and the connection to the street. Just a thought. FWIW, I also wouldn't muck around in the interior circuit breaker box, but that's me.

Yep I looked and dug around all along the side of the house where the electric meter is, the main panel is on the inside wall opposite the meter. No ground rods, no wires nothing!

The main house is over 100 years old while the addition where the meter and panel is is about 40 plus years old.

 

[jackj]

You know that 120v is half of 240v but do you know that your 120v outlets are wired to one side of the 240v and ground? If you have a bad ground then you will have bad voltage regulation on your 120v service. It will always add up to 240v but one side might be 150v while the other side will read 90v. Some of the older houses in our area don't have their own grounds, they depend on the ground at the pole transformer. There is nothing wrong with this as long as the ground is good at the pole. The ground at the house is just insurance in case the power company's ground goes bad. In any case, you need to get an electrician to look at your house wiring and make any needed repairs.

 

[jim202]

Even on the real old houses, the electrical code has always required a ground at the meter. There should be a wire coming out of the bottom of the meter box that is a ground. It should go down and to a ground rod. With your house being 100 years old, I would have expected that there would have been at least one upgrade to the electrical service.

Way back when, the wiring was done with what is 2 wires and ceramic insulators holding it away from the wood. There should not be many buildings left with this type of wiring today. Even the meter pans have been changed out. There is the slight possibility that over the years, the ground wire came off the ground and someone cut it off the bottom of the meter box. Take a look and see if you can see the remains of a solid wire at the bottom of the box.

If you can't find the ground wire, then it would be in your best interest in safety to call in an electrician to fix the problem. Your relying on the electric company neutral wire to maintain the ground in your house. Not a good position to be in. If the neutral comes loose anyplace, your 240 volt feed will wrack havoc to the electrical appliances in the house. You will see the light get brighter in one part of the house while they get dimmer in another as items get turned off and on.

 

[fredg]

Yes, when the addition was added maybe 30-40 years ago a new panel was put in along with some new runs. They however didn't run ground wires to the outlets so I have three prong outlets with no ground wire.

There is zero evidence that there was ever a ground wire on the electric meter, no remnants, no holes nothing.

About 3 years ago the electric company replaced the meter with a new digital one and replaced the main feed line to the house. I would have assumed that if a ground was needed they would have done it or at least informed me that I needed one.

In the end I have decided to follow the advice on this page Antenna Lightning and Surge Protectors - K3DAV.com - Amateur Radio Operator and run a piece of coax back out the entry point of the coax then I will unhook the radio and connect the coax to this short piece hanging outside. This will be the default setup unless I want to listen then it is a simple matter of swapping the coax from the outside line to the radio (I didn't explain that very well, see the website I linked above under the section "So How Can You Prevent Lightning From Hitting Your Radio?" for a more clear explanation.

Thanks for all the help in sorting this out!

 

[LtDoc]

There is NO sure-fire method of preventing damage from a lightning strike or a near one. You can certainly reduce the risk, but there's always a possibility of damage. The 'other' route to your equipment is through the ground system, no matter how good it is. If you disconnect the antenna system completely but leave the equipment grounded you can still have damage. No way of winning absolutely.
Probably the 'best' system is the one that commercial broadcast stations use. They have 'both' sides of the antenna "grounded" through an inductive ground. The 'normal' shield side to ground and the center conductor of the feed line to ground also. That 'center conductor' is grounded through an inductor which has a very heigh impedance at the frequency of use, so it doesn't allow signals at that frequency to go to ground, only the thingys not on that frequency. It's still not 'fool-proof', but it's got a humongus chance of by-passing the 'bad stuff'.
Sound a little 'unbelievable', yeah, but it works. If you are only talking about using one band (11 meters for instance) it's certainly 'do-able'! If multiple bands, then it get's a bit more difficult, sort of.
Ain't no absolute 'sure thing'. Wish there was...
- 'Doc

 

[fredg]

If you disconnect the antenna system completely but leave the equipment grounded you can still have damage. No way of winning absolutely.

I'm only going to connect the antenna in good weather otherwise I will have the end connected to a piece of LMR400 hanging out the window. Then use a battery powered handheld scanner only when I do hook into the antenna (in reality I will still probably use my desktop scanner but it's not grounded or anything since even my wall outlets are not grounded and it runs off a 12V AC adapter anyway LOL)

About as safe as you can get short of taking the antenna down altogether!