different size grounds-solar

[Klockopotomis]

So i just did a service change for a solar contractor and I used #4 Cu for the ground rods and also for the water pipe ground. Solar guy is telling me I need #6 for the water bond and #4 to the ground rods.
This doesn't make any sense to me. I have it sized correctly according to incoming feeder size. But an equipotential plane has to exist in the grounding system. All wires have to be the same size to there is an equalizing. Am i missing something?

 

[electrofelon]

So i just did a service change for a solar contractor and I used #4 Cu for the ground rods and also for the water pipe ground. Solar guy is telling me I need #6 for the water bond and #4 to the ground rods.
This doesn't make any sense to me. I have it sized correctly according to incoming feeder size. But an equipotential plane has to exist in the grounding system. All wires have to be the same size to there is an equalizing. Am i missing something?

Yes. You are missing all the BS that gets spread at the supply house while waiting for your order to be picked (second time today I used that one):lol:. The solar guy is talking nonsense and thas the sizes backwards (for a typical 200 amp service).

 

[Klockopotomis]

I guess I’m wondering how the Solar guy came to this conclusion of always needing a #6 to the ground rods

 

[gadfly56]

So i just did a service change for a solar contractor and I used #4 Cu for the ground rods and also for the water pipe ground. Solar guy is telling me I need #6 for the water bond and #4 to the ground rods.
This doesn't make any sense to me. I have it sized correctly according to incoming feeder size. But an equipotential plane has to exist in the grounding system. All wires have to be the same size to there is an equalizing. Am i missing something?

How would wire size affect the creation of an equi-potential plane? As long as you meet the minimums, who cares if you up-size one conductor or the other?

 

[electrofelon]

I guess I’m wondering how the Solar guy came to this conclusion of always needing a #6 to the ground rods

The GEC to the rods never needs to be larger than 6 (but can be). Perhaps you misspoke, there is a discrepancy between your two posts.

 

[Klockopotomis]

im sorry yes i quoted him wrong the first time. Solar guy says #6 for ground rods and #4 for cold water. Last year I failed a service change because I did just that, inspector said all system grounds had to be the same size so that one ground did not have less resistance than another, an equipotential plane.
I have never come across it in the code book before tho

 

[electrofelon]

im sorry yes i quoted him wrong the first time. Solar guy says #6 for ground rods and #4 for cold water. Last year I failed a service change because I did just that, inspector said all system grounds had to be the same size so that one ground did not have less resistance than another, an equipotential plane.
I have never come across it in the code book before tho

Alas, the "equal" in "equipotential" does not refer to the resistance of the conductors to the electrodes - thats not what we are trying to make "equal"