Ground Rod

Archive Public Archive
1

Originally Posted By: jpope
This post was automatically imported from our archived forum.


Never mind the clamps icon_rolleyes.gif How much is to much for one ground rod?






--
Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738

2

Originally Posted By: gbeaumont
This post was automatically imported from our archived forum.


WOW icon_eek.gif


Thats a new one on me I have seen 2 before, I am not sure if it's an issue though. I'll check later.

regards

Gerry

--
Gerry Beaumont
NACHI Education Committee
e-mail : education@nachi.org
NACHI phone 484-429-5466

Inspection Depot Education
gbeaumont@inspectiondepot.com

"Education is a journey, not a destination"

3

Originally Posted By: jpeck
This post was automatically imported from our archived forum.


That flexible metal conduit should not be there, it creates all kinds of problems.

–
Jerry Peck


South Florida

4

Originally Posted By: jpope
This post was automatically imported from our archived forum.


Please Jerry, continue. . .

–
Jeff Pope


JPI Home Inspection Service


“At JPI, we’ll help you look better”


(661) 212-0738

5

Originally Posted By: Charles Palmieri
This post was automatically imported from our archived forum.


I would be interested in hearing some history on flex also, but I think that might be armored covered bare conductor there is quite a bit of it existing in the NE.

6

Originally Posted By: jpeck
This post was automatically imported from our archived forum.


Jeff,


That kinda looks like BX, or maybe 3/8 FMC (flexible metal conduit)

Looking at the photo, either 1) the metal spiral wrap is in the clamp and not the grounding conductor inside it, or 2) the conductor is in the clamp and not the metal spiral wrap.

The problem with 1) is that the metal flexible conduit, which is a spiral wrap, is not rated to be used as a ground path, for basically anything. And that the ground conductor is not connected, which is also bad.

The problem with 2) is that the ground conductor is now covered with a metal shield, which must be bonded to the ground conductor at each end. Also, being as the flexible metal conduit is not rated or approved for use as a ground path, using it clamped to the ground conductor at each end makes it part of the ground path. Part of the ground current will be going through that FMC, like parallel conductors. When you use EMT or rigid conduit for that protection, it is also required to be bonded to the ground conductor at both ends, but they are approved for use as a ground path.

With conduit, you can think of it as one length of metal x feet long. With FMC, you would have to consider it as a spiral wrapped conductor, much longer than what you see, but most importantly, it is spiral wrapped around the ground conductor, making a choke coil.

A choke coil 'chokes' out ac current while allowing dc current to pass. The current which is trying to pass through the choke coil (in the wrap of the conductor itself) is ac, and is ac in the conductor going through the choke coil (the ground conductor). This would try to 'resist' and stop or at least impede the flow you so desperately need at the time you desperately need it. And the more you need it (higher ground current), the more it will impede (choke) itself.

--
Jerry Peck
South Florida

7

Originally Posted By: kmcmahon
This post was automatically imported from our archived forum.


Man…what I could learn by spending a week riding around with Jerry! icon_cool.gif

–
Wisconsin Home Inspection, ABC Home Inspection LLC


Search the directory for a Wisconsin Home Inspector
8

Originally Posted By: jtedesco
This post was automatically imported from our archived forum.


More comments to be considered by the HI:


The type of ground clamp used in the picture is one designed for a "water pipe, or water tubing." They are listed for that purpose by UL. Look at one when visiting the supply house.

This is common, but is still not correct and may be a good point to mention.

These "fittings or device's are not designed to be used on a ground rod (electrode), instead an "acorn" type clamp should have been used.

Also, the rod when driven to the full depth of 8 feet, will show an installation that is correct.

As far as the "grounding electrode conductor" with the metal armor covering, it is a product that is designed to provide the protection for the so-called physical damage that it may encounter during its life. It is not BX or Greenfield.

The choke coil discussion is very technical in nature and when discussed in detail in the Soares book on grounding supports Jerry's short story.

--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

9

Originally Posted By: Bob Badger
This post was automatically imported from our archived forum.


This armor covered bare is (or was) a common product in my area and when installed properly the bare copper is the conductor with the steel flex bonded at both ends to mitigate the ‘choke’.


The right clamps for this that I have seen have a clamping section for the armor and a screw for the copper conductor.

--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

10

Originally Posted By: dvalley
This post was automatically imported from our archived forum.


I’m still curious if this many grounds are allowed on one rod!


Does anyone have a code pertaining to the quantity of conductors that are allowed on a single 8 ft. rod?

--
David Valley
MAB Member

Massachusetts Certified Home Inspections
http://www.masscertified.com

"Some cause happiness wherever they go; others, whenever they go."

11

Originally Posted By: roconnor
This post was automatically imported from our archived forum.


]

–
Robert O’Connor, PE


Eagle Engineering ?


Eagle Eye Inspections ?


NACHI Education Committee


I am absolutely amazed sometimes by how much thought goes into doing things wrong
12

Originally Posted By: Bob Badger
This post was automatically imported from our archived forum.


dvalley wrote:
I'm still curious if this many grounds are allowed on one rod!


As many as you want / need ![icon_smile.gif](upload://b6iczyK1ETUUqRUc4PAkX83GF2O.gif) really, there is no limit and if you had separate rods for different services or systems (cable TV, Phone etc.) the NEC would require them to be bonded together anyway.

If you want you can go from the panel to the ground rod(s) then connect again to the rod to run to the water pipe.

Here is an example where the water pipe is used as a splice point for other electrodes but the same could be done with the ground rod.



From the NEC Handbook.

www.nfpa.org

--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum
13

Originally Posted By: tallen
This post was automatically imported from our archived forum.


Hey, ya’ll what’s the definition of a UFER? icon_biggrin.gif

–
I have put the past behind me,


where , however, it now sits, making rude remarks.


www.whiteglovehomeinspections.net

30 Oct 2003-- 29 Nov2005
14

Originally Posted By: jpope
This post was automatically imported from our archived forum.


Quote:
During World War II, a retired Vice President of Underwriters Laboratories, Herbert G. Ufer, developed it for the U.S. Army.


The Ufer grounding system ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)

http://www.scott-inc.com/html/ufer.htm

--
Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738
15

Originally Posted By: roconnor
This post was automatically imported from our archived forum.


Todd … UFER is the term used to describe a “Concrete-Encased Grounding Electrode”


Its steel reinforcing bars encased in concrete that are used as the "earth ground" ... see IRC E3508.1.2 or NEC 250.52.A.3 for more details. And now ya also know who it was named after too ... ![icon_wink.gif](upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif)

--
Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee

I am absolutely amazed sometimes by how much thought goes into doing things wrong

16

Originally Posted By: Bob Badger
This post was automatically imported from our archived forum.


If you really want to be technical a true ufer grounding system is much more elaborate than the 20’ of rebar in concrete that NEC considers a concrete encased electrode.


But many people refer to it as a ufer even if it is not. ![icon_cool.gif](upload://oPnLkqdJc33Dyf2uA3TQwRkfhwd.gif)

--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

17

Originally Posted By: Charles Palmieri
This post was automatically imported from our archived forum.


This site is a PDF file for O-Z GEDNEY Clamps the MA 5 Type is is advertised as suitable for connection to ground rods.


the GC is suitable for bare conductor


the GCA is suitable for ARMORED CONDUCTOR


the GCH apparently has a hub for metallic raceways


I do not know when this product became available the picture appears to be an installation that has existed for quite a while


http://www.o-zgedney.com/PDF/MA1thru12.pdf

18

Originally Posted By: roconnor
This post was automatically imported from our archived forum.


for dial-up users … that is a big file just to get to that one page (not the best set up for a catalog … icon_rolleyes.gif ) … so here is a pic of a similar reversible clamp :




--
Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee

I am absolutely amazed sometimes by how much thought goes into doing things wrong

19

Originally Posted By: roconnor
This post was automatically imported from our archived forum.


is that there is a special provision for attachment to ground rods (e.g. grove or “wings” to securely attach to a rod when the clamp is reversed).

–
Robert O’Connor, PE


Eagle Engineering ?


Eagle Eye Inspections ?


NACHI Education Committee


I am absolutely amazed sometimes by how much thought goes into doing things wrong
20

Originally Posted By: dedwards
This post was automatically imported from our archived forum.


I would guess that roughly 85% of the homes I inspect have the Weaver clamps installed on the ground rods instead of Acorn clamps. Most of the time they are tightened down as far as the screws will go and you can still rotate the clamp around the rod. I write them up every time and almost every time I hear “It was put on when the house was built” and like Mr Tedesco said…It still isn’t right. Often the clamp is so corroded it is almost completely gone and on occasion it is. The thing that amazes me is that the Acorn clamp costs exactly the same as the Weaver clamp and is marked “Direct burial”.