# Lightning arrester grounding?



## Dennis Alwon (May 9, 2009)

I don't understand what or how you are measuring. You cannot get a good reading with an ohmeter if you are trying to get an ohm reading of the rods to earth. 

I am not sure what you are trying to measure-- if the rods are connected together than you should get virtually 0 ohms... Please explain more


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## CBrown2418 (Jun 22, 2011)

I'm using a fluke 1632 earth grounding clamp meter. I can test the ground wire between the rods and its good but where the wire comes off of the ground rod to the trailers I'm getting the 450 ohm's. sorry if my spelling or words are wrong my phone loves to autocorrect words that don't need it and sayings that don't need it.


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## wildleg (Apr 12, 2009)

did you read the manual and follow the instructions for the(oops) stakeless ground loop measurement ? (you stated 1632 but isnt this acutally a 1623, 25, or 21 ?

http://www.instrumart.com/assets/1623-manual.pdf


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## Dennis Alwon (May 9, 2009)

I am still unclear. If you disconnect all wires except the ones tying the rods together, is that where you get 14-23 ohms--- I am surprised if that is the case. 

Still not sure how you are measuring the 1/0


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## wildleg (Apr 12, 2009)

in case you didn't read the manual, you might have missed this:



> *Is the result of a “Stakeless ground loop measurement”
> reliable?​*Ensure that you are using the correct inducing clamp (see
> “Recommended Accessories”)!
> The clamp’s parameters are suited for this test method. Using an
> ...


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## CBrown2418 (Jun 22, 2011)

I'm sorry I meant 1630 I didn't have it my hand. The problem is that our contract said that we are to drive the ground rods and connect them to the trailers. I did that but when they test it with their 1630 that's where it's showing the differences.


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## Jlarson (Jun 28, 2009)

I don't really get what the problem you think you have is.

The real issue I see is it sounds like this is a cobbled up lightning protection system, and the client has no clue what to spec and what to test. 

Are you rods spaced properly, are they all bonded together, is the LPS bonded to the existing electrical grounding system? These are the biggies but there are a lot of other things to be considered. You can't just stick some pointy rods on the roof and slam some rods into the dirt and call it good.


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## CBrown2418 (Jun 22, 2011)

The rods are properly spaced and the Lps that came on it looks good and it isn't part of the trailers grounding system for the electrical. It's the engineers that over think what they are doing and won't sign off until his meter is reading the right ohms before he can sign off on these as protected.


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## brian john (Mar 11, 2007)

CBrown2418 said:


> The rods are properly spaced and the Lps that came on it looks good and it isn't part of the trailers grounding system for the electrical. It's the engineers that over think what they are doing and won't sign off until his meter is reading the right ohms before he can sign off on these as protected.


 
There should only be ONE GROUND SYSTEM, you are using a 3-point test with a clamp?

How far out did you drive your test probes?
How many test did you make? 10%, 20%.................. of the distance to C3?

What are the engineers asking for?


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## CBrown2418 (Jun 22, 2011)

The engineer is using the stakeless fluke 1630 tester. I know they aren't 100% accurate but they are reading correct between the ground rods which eliminates that being the problem. Just such a huge jump of ohms going up to the Lps on top.


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## brian john (Mar 11, 2007)

CBrown2418 said:


> The engineer is using the stakeless fluke 1630 tester. I know they aren't 100% accurate but they are reading correct between the ground rods which eliminates that being the problem. Just such a huge jump of ohms going up to the Lps on top.


Where is it tied to the utility, if you are reading in the wrong place NOTHING MEANS NOTHING.


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## CBrown2418 (Jun 22, 2011)

There is no power out there yet just set the trailers and grounding the Lps. You do get ohm on the grounding with a proper tester which we are getting just changing from the ground rod up


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