Lightning rods?

[Runestone]

We had our first thunderstorm last night...which is way too early for this neck of the woods. However, it got me thinking about our brand new outbuilding with its beautiful metal roof. All the old barns I see around here, as well as a lot of the old farmhouses have lightning rods. I don't recall seeing many on new buildings even those with a metal roof.
Are lightning rods a thing of the past or should we be looking at installing them on this building?

[uncle Will in In.]

I haven't seen any new lightning rods put up for many years. Some of the older steel roofed barns had a ground cable hooked to the roof, going down to a ground rod. All my buildings have steel roofs including the house. Not a ground cable or lightning rod on any of them.

[Marilyn]

I didn't sleep well in my metal-roofed cabin until my kids chipped in and had lightening rods installed. They're the greatest! (the kids and the rods)

Two homes on this road were struck by lightening in 2-3 years. One burned to the ground, one damaged. I am very grateful for the lightening rods.

[Country Doc]

I have them on a three story house that sits on a hill of iron ore next to a pond and spring. They work great. I have a couple of suggestions for people installing them. First, not many people know how to put them in anymore. In Texas the oil wells often have them, so the experts are working the oil rigs. Also the wiring to ground the strike is bare heavy gauge copper. Make sure they don't lay the wire across your heating cooling wires etc like they tried to do with me. I almost had a lighting rod to direct the strike into the house.

[Tracy Rimmer]

The house we've bought in MB has a lightning rod -- but it's a century home, and probably had it installed from the beginning It's a 2 1.2 storey brick.

Could someone tell me the purpose of the blue glass ball that is attached to it, and does this need replacing? There are two "spares" inside the house -- and I don't know if they are prone to breaking, or if they need replacing after a strike?

[Rita]

After having seen several neighbors' homes get struck my brother in FL just had 3 or 4 installed (one for each peak) to the tune of $l,000.

[Liese]

We have 3 lightning rods on our roof, they are attached to a spirallying shaped wide copper piece that goes down to the ground, on some the copper bends at a 90* turn and continues alongside the foundation, then stops. Others seem to have lost heir 90* connection and just end at the gound but not into the ground. Could I have some suggestions as to how to make sure this system will actually work properly? Do we need to get those copper pieces going out away from the house and what could I connect them to so as not to have a mismatched metal problem?

[Ford8N]

Originally Posted by Tracy Rimmer

The house we've bought in MB has a lightning rod -- but it's a century home, and probably had it installed from the beginning It's a 2 1.2 storey brick.

Could someone tell me the purpose of the blue glass ball that is attached to it, and does this need replacing? There are two "spares" inside the house -- and I don't know if they are prone to breaking, or if they need replacing after a strike?

Keep those spares. They are collectible now. Just go to ebay and take a look. How much they are worth depends on the color and type of glass insulator. The balls were mainly for decoration and partially to tell you if lightning had struck the rod. Other than that they served no purpose. Most fell victim to kids using them as target practice.

[Tracy Rimmer]

Thanks, Paul. They're really pretty, but I didn't know if they served a purpose or not, and if I ran out, where would I get them They're probably the same age as the house!

[fordy]

......................Just too clarify , lightening rods , are NOT , installed to Dissipate a Direct strike !!! Rather , they are UP there to dissipate any static charge buildup that might possibly attract a stike of the opposite polarity . If , a static charge has a low or no resistance pathway too ground it will never buldup . Any structure properly prepared to dissipate a direct hit has had lots of money and engineering to properly accomplish such .
.......................All telephone poles are equipped a ground wire consisting of a run of #6 solid copper which is the standard I believe . #6 wire would also be the size to use should anyone pay another to install a system . 310 foot rolls of #6 use to be available for purchase at H.Depot for 50 or so but are probably 200 or so at todays prices , IF they are still available . fordy...

[ET1 SS]

Originally Posted by fordy

......................Just too clarify , lightening rods , are NOT , installed to Dissipate a Direct strike !!!

Except of course for the fact that they do.

... Rather , they are UP there to dissipate any static charge buildup that might possibly attract a stike of the opposite polarity . If , a static charge has a low or no resistance pathway too ground it will never buldup .

True.

... Any structure properly prepared to dissipate a direct hit has had lots of money and engineering to properly accomplish such .

???

.......................All telephone poles are equipped a ground wire consisting of a run of #6 solid copper which is the standard I believe

Wow, it has been years since I have seen regular poles like that.

I do recall seeing them long ago, where most poles had grounding,

I have eight power poles on my land [four going South and four going North] and only one of them has a grounding strap. That is because it is the transformer for my house. None of the other poles have a ground-strap.

Around here electrical power is up on the poles, while telephone and DSL is underground.

.... #6 wire would also be the size to use should anyone pay another to install a system . 310 foot rolls of #6 use to be available for purchase at H.Depot for 50 or so but are probably 200 or so at todays prices , IF they are still available . fordy...

Regular grounding strap works much better. It can handle the current, where solid conductor can not.

Grounding strap is braided wire, more electrons tend to flow along the surface of the conductor than through the center of the conductor. So a big gauge wire can not handle the same current flow as a braided cable can handle.



Or you could ask an Electronic Tech who has worked with grounding straps about it, are there any ETs here? Any ET1s, ETCs?

[quietstar]

Consider me an outmoded E.T. who agrees in general about grounding straps. I'm building a new cottage on an old homestead tract that has the remains of the origional home, vacant for about 75 years and falling down. Shining bright there is a large array of lighting rods and connecting/grounding woven round cable. No evidence of lighting damage and makes me think about moving it to my new construction. My "Shade home" design is a steel structure protecting a seperate, highly insulated living "box" so it might be wasted effort. Thoughts anyone...Glen

[fordy]

Originally Posted by ET1 SS

Except of course for the fact that they do.





True.





???





Wow, it has been years since I have seen regular poles like that.

I do recall seeing them long ago, where most poles had grounding,

I have eight power poles on my land [four going South and four going North] and only one of them has a grounding strap. That is because it is the transformer for my house. None of the other poles have a ground-strap.

Around here electrical power is up on the poles, while telephone and DSL is underground.





Regular grounding strap works much better. It can handle the current, where solid conductor can not.

Grounding strap is braided wire, more electrons tend to flow along the surface of the conductor than through the center of the conductor. So a big gauge wire can not handle the same current flow as a braided cable can handle.



Or you could ask an Electronic Tech who has worked with grounding straps about it, are there any ETs here? Any ET1s, ETCs?

.................Grounding strap does work better because the current travels along the surface of the metal (Hysteris?) , Better than a solid copper conductor . But , it is also expensive and probably is much more vulnerable to rough treatment than a solid piece of copper wire .
.................I'm sure there are lightening systems installed on homes that have rece'd a direct hit and survived but they would be exception rather than the rule !
..................Around here , in texas , ALL power poles have a run of #6 copper running down the pole and usually they will form a coil of wire and staple it too the flat bottom of the pole prior to setting the pole . Even , the little 12 footer that has a "drop" hanging on it that my trailer is plugged into has a ground . And , when a power wire say at 7200 volts takes a direct hit it is supposed to be channeled too ground thru the center tap of the stepdown transformer
but of course it probably will be allowed to enter the home where it will run amuck and dissipate it's energy thru destruction inside the home .
..................In texas , the Power(hot) Wire(s) are always on TOP of the poles and the single ground wire is Below ! Why they are constructed in this manner makes NO sense to me. Because , obviously , a lightening strike is usually associated with connecting with the "highest" point on any structure which should\would be the ground wire . Also , since each pole has a ground a direct hit should be able to dissipate it's cumulative energy ...Out...over several telephone poles(?) .
...................I'm not an expert but a home is safer , With a grounding system , than With...Out ! And , again the systems for residential structures , normally can't handle a large , direct strike , although anything is possible . What most folks don't have any clue about , is that , Ground conductivity is a Variable , and NOT fixed . Just because a knowledgeable installer has installed a system with all the right equipment , IF he didn't measure the Conductivity of the soil , where he installed his ground rods the system may , virtually BE USELESS . So , some type of remedial action on the installers part will be necessary to ensure that his ground is a Very low resistance so as to allow the system to dissipate a large charge when called upon ! fordy...

[fordy]

Originally Posted by quietstar

Consider me an outmoded E.T. who agrees in general about grounding straps. I'm building a new cottage on an old homestead tract that has the remains of the origional home, vacant for about 75 years and falling down. Shining bright there is a large array of lighting rods and connecting/grounding woven round cable. No evidence of lighting damage and makes me think about moving it to my new construction. My "Shade home" design is a steel structure protecting a seperate, highly insulated living "box" so it might be wasted effort. Thoughts anyone...Glen

...............Salvage as much of the "metal" as you safely can and then consult with a qualified person who installs these systems . Copper sells on the recycler market for high prices so don't think it doesn't have any value . fordy...

[ET1 SS]

Originally Posted by quietstar

Consider me an outmoded E.T. who agrees in general about grounding straps. I'm building a new cottage on an old homestead tract that has the remains of the origional home, vacant for about 75 years and falling down. Shining bright there is a large array of lighting rods and connecting/grounding woven round cable. No evidence of lighting damage and makes me think about moving it to my new construction. My "Shade home" design is a steel structure protecting a seperate, highly insulated living "box" so it might be wasted effort. Thoughts anyone...Glen

As someone who is living inside of a steel building. Each individual piece of metal [like the metal roof, and the sheets of wall] may be physically holding onto it's neighbors; but that does not mean that there exists any form of electrical connection between them.

You could very easily have an entire building, and only 10% of the pieces of metal actually connected to each other. It may simply be a large pile of dis-connected metal. Even though it is a wonderful house, well insulated thermally and very comfortable inside.

I was really amazed, once I was done constructing the shell; to find that the roof measured infinite resistance to ground. It had no path for current flow at all.

I had thought that metal screws going through the roof panels, into steel rafters, bolted onto steel girders, would provide a fairly good electrical connection. But it did not.

I have three ground rods driven in the ground, at ten foot intervals, with grounding strap connecting them to each other and connecting them to each steel girder. I have a ground strap soldered onto each girder and onto the angle-irons that rest on the foundation, along the entire perimeter of my house. Every wall panel rests on the foundation and is screwed into the angle iron. And they test as 'grounded'. ...

And now after spending a week grounding my new house, I am confidant that even the roof is grounded.

Though I learned a lesson.

[ET1 SS]

Originally Posted by fordy

... Grounding strap does work better because the current travels along the surface of the metal (Hysteris?) , Better than a solid copper conductor.

... I'm sure there are lightening systems installed on homes that have rece'd a direct hit and survived ...

... I'm not an expert but a home is safer , With a grounding system , than WithOut...

Statements that I agree with.