Lightening Protection

[RichB]

Ok Just got straightened out on LPS and Grounding--Now the question is--Here is the appropriate point to bond LPS and Grounding Electrode system---Do you bring the LPS into the premise and bond at the point you terminate the GEC or do you bond at the Grounding Electrode itself?

I need to get all these darn ducks re-lined up so I can go back and give the proper answer--Seeing as how I misinterpreted this from the start:?:ashamed1: and caused some confusion and discontent:slaphead:

Thanks folks--I really appreciate this!!

Rich

 

[mgookin]

If you want the lightning to go into the Earth it seems the electrode would be the place to make your connection. Otherwise it will have to go through more conductors and connections to get there.

 

[LightningProtectionDesign]

There are a couple of different ways to interconnect the two systems, the most obvious being if both systems ground electrodes are accessible, to connect the two grounding electrodes together. If a lightning protection down conductor happens to run through the electrical room, you can go from the lightning conductor to the electrical ground, building steel, bus bar, or even the metallic water pipe as long as it is electrically continuous between the two systems. The main thing to remember is the wire must be equal to or larger than the main-sized lightning conductor, and any clamps/fittings used should meet the requirements for lightning protection.

The lightning protection needs to be interconnected to all grounding media, and any metallic piping entering the building. So if there is metallic water pipes, gas lines, fire sprinkler system, telephone, cable, satellite, they should all be interconnected.

 

[RichB]

If you want the lightning to go into the Earth it seems the electrode would be the place to make your connection. Otherwise it will have to go through more conductors and connections to get there.

Thanks!!

That is what I was thinking--you know kinda obvious--but then obvious is not always correct

 

[RichB]

There are a couple of different ways to interconnect the two systems, the most obvious being if both systems ground electrodes are accessible, to connect the two grounding electrodes together. If a lightning protection down conductor happens to run through the electrical room, you can go from the lightning conductor to the electrical ground, building steel, bus bar, or even the metallic water pipe as long as it is electrically continuous between the two systems. The main thing to remember is the wire must be equal to or larger than the main-sized lightning conductor, and any clamps/fittings used should meet the requirements for lightning protection.

The lightning protection needs to be interconnected to all grounding media, and any metallic piping entering the building. So if there is metallic water pipes, gas lines, fire sprinkler system, telephone, cable, satellite, they should all be interconnected.

Thanks!! That makes sense--Next question now is,,,,

Is this a smart thing to do?---I mean we are trying to direct the energy in a lightening event to ground to dissipate the affects on the system and keep it out/off of our equipment as much as possible--So why route it into a structure or building and why bond it to our grounding system?---If the intent is to minimize the voltage gradients between the systems then this sounds like, to me, driving a ground rod to minimize the voltage gradients at a ground fault so you don't get shocked touching the affected metal part, i.e., the light pole--

but I am obviously not wrapping my head around this correctly or am missing something, so please!!!!! feel free to educate me on this!!

 

[iwire]

I don't understand why you think a hard bond between systems is the equivalent to using a ground rod to clear a fault.




I would say the reason we bond the two systems together is to keep the potential between them as low as we can.

 

[RichB]

I don't understand why you think a hard bond between systems is the equivalent to using a ground rod to clear a fault.




I would say the reason we bond the two systems together is to keep the potential between them as low as we can.

ok--I don't--I think--:?

Let's see if I can explain it a bit better

It sounds like the same thing--If you bond the LPS and service grounding together to minimize the potential between them--I can't seem to get a drawing to upload today so picture the ground rods bonded together--then an event happens--oh,,

Never mind--I got it!!! Light bulb just went on--

So then the only question I still am not getting is-- Since this is now in parallel-- do we want to bring that energy into our---oh damn--Another light bulb---It already is in parallel due to the fact that the Service Entrance Conductors coming from the Poco come in and they will also carry the high voltage/energy from a lightening event--therefore with our systems bonded it helps to create an quicker reference to earth for that pulse, in addition to what Poco does at the transformer--ok---DUH OH!!


Thanks guys, and iwire in particular, for making me think this out--I just could not make the connection!

If I still am off base please holler and let me know how!!

Thanks again!!

Rich