- Location
- Massachusetts
mdshunk said:
I bet almost never....and I doubt any harm has come from this possible oversight.
Now if we change to utility distribution systems I think the electrodes might be helpful.
Gnd rod in handhole
- Thread starter chris kennedy
- Start date
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I bet almost never....and I doubt any harm has come from this possible oversight.
Now if we change to utility distribution systems I think the electrodes might be helpful.
chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
How many of you carry testers for this? I've gotten into the habit of driving the additional rod. How much are these testers?
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
I call these time and material ground rods as they serve no usefull purpose.
Ask the engineer what they are for, I would be really curious as to the justification.
Ask the engineer what they are for, I would be really curious as to the justification.
mdshunk
Senior Member
- Location
- Right here.
I drive two rods, and I own the tester. I only own the Megger DET3 point tester for my own personal amusement and entertainment. Plus, I have some sort of fundamental malfunction that causes me to want to own such gadgets. :wink:chris kennedy said:
chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
mdshunk said:
It's a chemical inballance. Testosterone.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Maybe the ground rods are there as sacrificial anodes 
Of course, whatever they are protecting would have to be less electronegative than the ground rod, so unless you are applying an external potential or protecting silver pipes, this wouldn't even work as a joke.
-Jon
Of course, whatever they are protecting would have to be less electronegative than the ground rod, so unless you are applying an external potential or protecting silver pipes, this wouldn't even work as a joke.
-Jon
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
Surely the ground electrodes are there to keep the local soil potential the same as the EGC, ie equipotential?
- Location
- Massachusetts
dbuckley said:
It may be why they where specified but the rods can not accomplish it.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
See the picture attached to post #2 of this thread.
A ground rod will bond the soil around the rod to the potential of the EGC. This will limit the voltage difference between the EGC and the _nearby_ soil.
The problem with thinking that this is at all useful is what is meant by 'nearby'.
If you were a mouse, then the local 'equipotential' region might make a difference
Say you have a ground rod that is at 120V relative to 'distant earth'. The soil right next to that ground rod will also be at 120V, so there wouldn't be a shock risk between the two. But (according to the picture) at a distance of only 3 feet from the ground rod, the soil will only be at 30V relative to 'distant earth'. This means a 90V shock potential between the ground rod and the soil.
-Jon
A ground rod will bond the soil around the rod to the potential of the EGC. This will limit the voltage difference between the EGC and the _nearby_ soil.
The problem with thinking that this is at all useful is what is meant by 'nearby'.
If you were a mouse, then the local 'equipotential' region might make a difference
Say you have a ground rod that is at 120V relative to 'distant earth'. The soil right next to that ground rod will also be at 120V, so there wouldn't be a shock risk between the two. But (according to the picture) at a distance of only 3 feet from the ground rod, the soil will only be at 30V relative to 'distant earth'. This means a 90V shock potential between the ground rod and the soil.
-Jon
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
If we are calling it a structure, are we installing a disconnect for the handhole in accordance with 225.31?
- Status