Shed Sub panel 2 rods or 1

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K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
For the average homeowner that is not into ham radio what benfit is provided by a good connection to dirt?

Actually, an earth connection is very over rated by ham radio operators and with few exceptions based upon antenna design, radios don't need an earth connection to work.

Now, if there are big towers, and those could be for things other than antennas, an earth ground is important.

Also, a good earth ground will mitigate some of the damage caused by an open neutral coming into the structure by providing a path for unbalanced current back to the transformer. In our local city where most of the water lines are still metal, lost neutrals sometimes aren't even noticed. I saw one completely severed on a house next to one we were working on in the city and the people that lived there didn't even notice it.

To earth or not to earth is a question with many answers. Lightning is usually involved in the discussion, but lightning is a fickle sprite and seemingly has a mind of it's own, so many dismiss the fact that an earthed system is needed for lightning protection.

I will tell you that it is. I have been in weather radar and 911 dispatch centers that operate while taking direct lightning hits and it's the engineered path to ground that saves the people and equipment.

Does a CEE or a couple rods provide that same protection from lighting or other surges in a residence? Some say no, but the NEC seems to think yes.

Also, we need to remember that each structure, no matter how flimsy the earthing is, contributes the to overall scheme of things concerning our multiple grounded neutral distribution system.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Personally, I don't think a near 1000 ohm connection is fine. It's a code minimum. We put in rods because we are allowed to and the customer doesn't care about a good connection to ground. At least a CEE works.

None of the above relates to whether or not an earth connection is good, bad or otherwise. It's just that two rods have been shown to be nearly ineffective in our area, but we have to use them anyway. If we are bound by code to use an earthing electrode, at least it should be one that has been shown to be effective.

The point is that what does "effective" mean as far as earthing goes for the vast majority of cases. In most cases a 1000 Ohm connection is quite adequate. There is this myth that somehow all bad things electrical can be shunted off into the Earth by a "good" earth connection. That is just plain false.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
The mitigation of a open neutral from a water pipe electrode is often the result of a low resistance metallic connection to the ground/neutral bond at a neighboring house on the same transformer rather than anything attributable to a low earth connection impedance.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
A warm fuzzy feeling is my guess.:)

Tell them you have installed 2 rods and they will usually just beam in unwarranted happiness.

I've yet to meet a homeowner customer that even cares about ground rods or what they do.

<rant>

If I could get back the time I've spent explaining to customers why we have to have the ground rods, and where the heck is an acceptable location to install them in their homes, and why they will not get electrocuted by the bare copper wire, blah blah blah, etc., I could maybe be retired by now.

<end rant>
 

kwired

Electron manager
Location
NE Nebraska
A warm fuzzy feeling is my guess.:)

Tell them you have installed 2 rods and they will usually just beam in unwarranted happiness.

I've yet to meet a homeowner customer that even cares about ground rods or what they do.

If they see me installing a second rod they usually have to ask why one isn't enough.

I also have a hard time explaining to them why I need to get a ground conductor to their footing on new projects, and worse yet convince them this is a better alternative to a ground rod.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
<rant>

If I could get back the time I've spent explaining to customers why we have to have the ground rods, and where the heck is an acceptable location to install them in their homes, and why they will not get electrocuted by the bare copper wire, blah blah blah, etc., I could maybe be retired by now.

<end rant>

I just ask them if they want to move in. Cause if I don't you won't move in until I do what the CODE requires.
And if you don't believe me ask the inspector.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I just ask them if they want to move in. Cause if I don't you won't move in until I do what the CODE requires.
And if you don't believe me ask the inspector.

I'm dealing with customers who already live in their homes. But same thing, the won't get their net metering credits if they don't pass inspection.
 
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