Ground rods in sidewalk

[roger]

No.

see 250.53(A)(4) - horizontal rods can only be installed in a trench and be code compliant

They don't have to be in a trench, it depends on the situation.

250.53(G)

(G) Rod and Pipe Electrodes. The electrode shall be installed
such that at least 2.44 m (8 ft) of length is in contact
with the soil. It shall be driven to a depth of not less than
2.44 m (8 ft) except that, where rock bottom is encountered,
the electrode shall be driven at an oblique angle not
to exceed 45 degrees from the vertical or, where rock bottom
is encountered at an angle up to 45 degrees, the electrode shall
be permitted to be buried in a trench that is at least 750 mm
(30 in.) deep. The upper end of the electrode shall be flush
with or below ground level unless the aboveground end and
the grounding electrode conductor attachment are protected
against physical damage as specified in 250.10.

Roger

 

[Nuber]

They don't have to be in a trench, it depends on the situation.

250.53(G)



Roger

For clarification - it is not possible while being code compliant - to DRIVE a rod horizontally. A rod is only allowed to be placed horizontally via burial in a trench. This is shown in your referenced code.

Technical point, doesn't make a lot of sense in the real world, but DRIVING a rod horizontally is still not allowed.

I am not saying it isn't possible for a rod to be installed horizontally, just that you can't drive it into the ground. You have to excavate and bury it.

 

[roger]

For clarification - it is not possible while being code compliant - to DRIVE a rod horizontally. A rod is only allowed to be placed horizontally via burial in a trench. This is shown in your referenced code.

Technical point, doesn't make a lot of sense in the real world, but DRIVING a rod horizontally is still not allowed.

I agree. For some unknown reason I had 45 degrees in mind.

Roger

 

[michaelanders27]

Master Electrician from Va here.

2ground rods is all I ever do no matter what. It just makes sense. Cold water grounds are less and less reliable with plumbing going toward pvc and pex these days.

Two rods along the other side of the sidewalk, driven below grade, cut across an expansion joint for the GEC to get to the first means of disconnect. Easy peasy.

I’ve had an inspector tell me he only wanted one ground rod because saw a line going to the incoming water supply. I had already driven two rods and then showed him where some plumber reconnected the ground clamp to the plastic pipe he had installed in place of the galvanized line. FYI, plastic is not a good conductor....

 

[Knuckle Dragger]

Some AHJ only require one rod because the town mandates that all the water services be copper so they see no need for the supplemental ground .
I know of one town that required 40 feet of copper before changing to PVC water service. (This was for the sole purpose of having something to connect the EGC to).

 

[roger]

(This was for the sole purpose of having something to connect the EGC to).

They obviously didn't know what the EGC's purpose is.

Roger

 

[jimport]

Is the 4" in the sidewalk not in contact with the earth going to make a difference at the end of the day?

 

[roger]

Is the 4" in the sidewalk not in contact with the earth going to make a difference at the end of the day?

Heck no, as a matter of fact the other 92" in contact with the earth won't either

Roger

 

[kwired]

I’d love for someone to explain to me how that requirement makes any sense, what if it measures 800 Ohms after installing second ground rod? Measuring isn’t a requirement after second rod is installed.

Ding ding ding ding ding, we have a winner. Ground rods are overrated to begin with. Nothing wrong with adding one at a service, even if there is no other electrodes at that service. Bottom line is it still is usually a relatively high resistance to ground, definitely is not much of a ground reference compared to the entire MGN network on the utility system and really isn't doing much by itself except being the closest electrode to the service in the event of a pretty direct lightning strike at the structure.

Inspectors get brainwashed in their certification training (they just have to) into thinking if you don't have these rods someone is definitely going to die or the house will definitely burn down because of it. Though there are thousands of structures that stood for many many years never having such an incident caused by no grounding electrode.

I do think still good idea to connect water pipe electrodes, CEE's, and structural steel when they are present. Adding a rod when none of those are present, I don't have too much issue with, but it isn't going to perform miracles either it is going to sit there at anywhere from maybe 15 to 100 ohms in most cases, and adding a second or third rod will make little to almost no improvement in many cases.

 

[kwired]

I have drilled about a 3 inch hole in sidewalk before then drive rod in that hole and below the surface. this gets your connector below the surface. Being right next to building of course so there is no tripping over the conductor, bend the rod a little so it will miss any footing that you might hit if driving straight down next to the building.

 

[GerryB]

Why are you adding ground rods for just a panel change?

In my area if it is getting inspected you are required to bring the grounding up to code, but if no permit that's a lot of extra work with with a concrete sidewalk.