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View Full Version : Grounding System required to be visible?



Matt Fellman
02-04-2009, 04:56 PM
99% of the new houses I see have a bond to the garage rebar just below the panel and/or rod(s) outside. Today's house has a cement walkway poured up against the house (likely over any ground rod) and the normal location for the rebar bond is a coaxial cable jack.

I took the plate off the cable jack and its one of those metal patches (like you use when someone puches a hole in the wall. I'm not sure if the rebar bond is in there or not.

Anyway, are these connections required to be visible/accessible?

Matt Fellman
02-04-2009, 04:58 PM
Oops... pictures

Roland Miller
02-04-2009, 05:04 PM
If it is a mechanical connection then it is required to be accessible unless --an encased or buried connection to a concrete-encased, driven or buried grounding electrode. The ground rod and connection would not be required to be accessible. If the rebar is stubbed up in the wall cavity and the connection is there it must remain accessible.

Matt Fellman
02-04-2009, 05:13 PM
I guess this leaves me confused on how to ask them to have access to something I'm not sure is present????

I wrote it up as have an electrician verify proper grounding since I cannot see any....

I strongly suspect someone patched over the rebar bond box and ran a coax cable through it.

Roland Miller
02-04-2009, 05:26 PM
That is a tough one. And you don't know for sure that the connection is not covered with concrete, which would be OK. Maybe just a note that you were not able to inspect the CEE because it was not accessible??

Jerry Peck
02-04-2009, 06:35 PM
I wrote it up as have an electrician verify proper grounding ...


That's the way I always wrote it up to, except that I added "while on site making other corrections", which means "no one has to pay for a special trip to check it".

Matt Fellman
02-04-2009, 06:56 PM
Thanks guys.... just to brush up, what and how many grounding sources are required?

When I was learning this business about 10 years ago I remember the guy training me said 2 or the following 3 were required:

Ground by metal plumbing
Ground by rebar to the foundation
Ground by rod into the earth

Since pretty much every house has plastic plumbing these days that one is out so it leaves the other two. As I posted initially, just about every house I see has the bond to the rebar beneath the panel. Am I to assume there is also a rod buried by gravel or cement also? Is what I was taught correct?

Jerry Peck
02-04-2009, 06:59 PM
When I was learning this business about 10 years ago I remember the guy training me said 2 or the following 3 were required:

Ground by metal plumbing
Ground by rebar to the foundation
Ground by rod into the earth


All that are available.

Which includes many more than state above 'if available'.

Remember, though, that most water service lines today are plastic and cannot serve as a grounding electrode. Interior metal water piping is "bonded to" the ground system, but not 'used as' a ground.

Jim Port
02-04-2009, 07:32 PM
If a CEE or Ufer ground method is used you do not need additional rods.

When rods are used unless less than 25 ohms of resistance can be proved a second rod is required.

Jerry Peck
02-04-2009, 09:11 PM
If a CEE or Ufer ground method is used you do not need additional rods.

For true concrete encased electrodes that is correct, however, many of the installations do not meet the requirements set forth in the code, thus additional electrodes are required (typically driven rods).