# Residential grounding



## Pcinspector1

I'm curious what other AHJ's are requiring for residential electrical service house grounding for the primary and secondary grounding due to the increase in plastic service line use.

In the old days we had a ground rod and house water service ground.

I'm seeing other jurisdictions allowing a piece of rebar sticking up through the concrete foundation at the top of the wall and others using a piece of rebar bending up out of the footer. Anybody allowing either of these grounding methods?

Anybody mandating a policy of copper waterlines only? 
Plastic not permitted with code amendment?

Anybody allowing TWO rods a minimum of 6-ft apart with a separate ground wire to each rod or allowing daisy chaining with one wire and three clamps?


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## steveray

Footing and foundation steel is required here so it HAS to be bonded anyway so that is fine (UFER or CEE) and no secondary is required. The supplemental is only required if you are using the water pipe...


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## fatboy

Ditto..............


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## mfichter80

It should be noted that the "piece of rebar" should be tied to at least 20 feet of rebar or #4 copper that is encased in concrete, and the concrete is supposed to be in direct contact with the earth.  And this means that if there is a vapor barrier between the concrete and the gravel, that is no good.

Also a lot of concrete these days uses reinforcing fibers or whatever in place of rebar, so in that case 20 feet of electrode material would have to be added to the concrete.

I was putting up a garage at my house, and was planning on doing this, and then when I talked to the inspector, he pointed out that there was a retaining wall on the corner I was running power to.  I always thought of the gravel as being "in contact with the earth" and I just wasn't thinking about the fact that the gravel on that side would be 2 or 3 feet deep.

So there can be a lot involved in making sure that piece of rebar is installed properly.

Generally around here 2 ground rods are required.

in the NEC, a supplemental electrode is only required when the primary electrode is a rod, or metal water pipe, not when it is a concrete-encased electrode.

Some localities are requiring Ufer grounds now that plastic water pipe is the norm.  

steveray or fatboy:  Do you know of an interpretation of an NEC code that calls for a required Ufer ground, or do you just see these as a decision that is made by the AHJ?


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## steveray

If the rebar is there, you have to hit it (bond as grounding electrode NEC 250.50 maybe or somewhere around there). WE can not require it (UFER) to be installed, just one of the choices the contractor makes...


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## mfichter80

steveray said:


> If the rebar is there, you have to hit it (bond as grounding electrode NEC 250.50 maybe or somewhere around there). WE can not require it (UFER) to be installed, just one of the choices the contractor makes...



Gotcha.  I think the inspectors where I used to work as an electrician interpreted that section to mean that if rebar is in the foundation, then they considered it to be an electrode that is present and must be tied to the system. But you're basically saying if the rebar doesn't have a connection point sticking out of the concrete, then it isn't present.  Which makes sense.

As an electrician I always recognized that the ufer ground probably should be required since it is much more effective than a rod, but I also knew that some localities over-stepped their bounds with their interpretations of the code.  Now I'm an inspector in a locality that doesn't require a bunch of extra stuff, and I've been trying to make sense of some of the differences.


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## steveray

I "make" them set up for it at footing and foundation inspections....There is some language in there about "present and available" (I believe) once they pour it is no longer available and you can't make them hit it. But let them try to get away with that more than once....They will be sending the concrete truck home full and waiting for the electrician to show up before they can pour...


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## Pcinspector1

The connection on a water pipe was to be accessible and before the first fitting. 

On a residential job, where are you guy's seeing the connection at the top of the foundation wall, stem wall or somewhere around the footing floor connection?

On commercial jobs I'll see a coiled grounding wire near the panel location before a frost footing is poured.

I'm currently allowing the water pipe connection and if it's been replaced with plastic, I ask for two ground rods minimum of 6-ft apart and they can daisy chain it, with three approved connectors. 

Was asked by a sparky if they needed to have individual grounding wires?


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## FLSTF01

The two ground rods should be connected with one continuous wire.  2014 NEC 250.53 (C) sends you to 250.64 (C) which states continuous or irreversible crimp or exothermic welding.


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## McShan

E3608.1 Grounding electrode system. All electrodes specified in Sections E3608.1.1, E3608.1.2, E3608.1.3, E3608.1.4 E3608.1.5 and E3608.1.6 that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these electrodes are present, one or more of the electrodes specified in Sections E3608.1.3, E3608.1.4, E3608.1.5 and E3608.1.6 shall be installed and used. (250.50) 

E3608.1.2 Concrete-encased electrode. A concrete-encased electrode consisting of at least 20 feet (6096 mm) of either of the following shall be considered as a grounding electrode:

1. One or more bare or zinc galvanized or other electri- cally conductive coated steel reinforcing bars or rods not less than 1/2 inch (13 mm) in diameter, installed in one continuous 20-foot (6096 mm) length, or if in multiple pieces connected together by the usual steel tie wires, exothermic welding, welding, or other effective means to create a 20-foot (6096 mm) or greater length.

2. A bare copper conductor not smaller than 4 AWG.

Metallic components shall be encased by at least 2 inches (51 mm) of concrete and shall be located horizontally within that portion of a concrete foundation or footing that is in direct con- tact with the earth or within vertical foundations or structural components or members that are in direct contact with the earth.

Where multiple concrete-encased electrodes are present at a building or structure, only one shall be required to be bonded into the grounding electrode system. [250.52(A)(3)]


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## Francis Vineyard

A bonding jumper or separate wire is permitted to bond the grounding electrode system together.  Illustrations below based on NEC 2014 provided as supplementary information towards this discussion.


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## Pcinspector1

Francis, good information. 

The accessibility question came up, which I see you provided a photo of the rebar (electrode) connection that would be accessible meeting E3611.2.


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## north star

*% = = %*


Does the "accessibility requirement" mean only for an inspection,
or "permanently" accessible ?

I always interpreted that Code Section to mean "permanently"
accessible.

FWIW, ...the image that ***Francis Vineyard'*** submitted of
an elec. connection in the wall [ seemingly  ] does not [ IMO ]
meet the Exception in Article 250.68(A) *"IF"* that wall becomes
enclosed.

What say ye ?


*% = = %*


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## Rick18071

I would say permanently.


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## Francis Vineyard

Here's another view


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## Pcinspector1

I assumed that the photo showing the GE connection would be accessible similar to the picture in post #15. 

Agree with Rick, it should be permanently accessible.


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## linnrg

been doing the stub up scenerio for several years and so this year a framing contractor did not like the rebar stub sticking up and just ground them off,  He was working nearby so him and his whole crew got educated on what they were for.

It seems that copper is fast going away (because of price) and HDPE has become the choice.  Our utility people had to re-specify proper fittings as soon as the HDPE came up inside.


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## steveray

IF it is a "DB" clamp or cad weld, it does not need to be accessible...


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## Pcinspector1

steveray said:


> IF it is a "DB" clamp or cad weld, it does not need to be accessible...



Clarification: Attached in a "DB" (direct bury) application, in the footing correct?


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## McShan

If its Direct burial would it matter?


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## mfichter80

NEC Article 100

Accessible (as applied to wiring methods).  Capable of being removed or exposed without damaging the building structure or finish, or not permanently closed in by the structure or finish of the building.

Readily Accessible.  -Capable of being reached quickly for operation, renewal, or inspection without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, and so forth.

The grounding electrode conductor connection should be made at an accessible point.  If the connection is a DB clamp on a rod, that's accessible because it's normally located a couple inches in the ground.


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## mfichter80

NEC 250.24 (A) (1)

"The grounding electrode conductor connection shall be made at any accessible point from the load end of the service drop or service lateral, etc., etc."


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## McShan

Francis where did you get your illustrations?


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## Francis Vineyard

NEC 2014 Analysis of Changes book


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