Grounding electrodes

[Nitrovoltage001]

What size grounding electrode do I need for a 300 amp service I have been told don't need bigger than #6 but I don't think that's accurate

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[infinity]

What type of electrode and what size are the service entrance conductors?

 

[Electrical Geek]

Table 250.66 goes off of the size of the conductors. If you don't have a metal underground water pipe and are using a ground rod, then you only need a #6 per 250.66(a)

 

[Little Bill]

What size grounding electrode do I need for a 300 amp service I have been told don't need bigger than #6 but I don't think that's accurate

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To "nit pick" a little, I think you are asking what size grounding electrode conductor (GEC). There are no sizes mentioned for electrodes themselves, only the conductors to them. As was mentioned, if using only a ground rod as an electrode, then #6 is all that is required. If using a Ufer, then #4 is required. There are a few other electrodes that require larger than #6. Of course, Table 266 is used to size them and some electrodes are exceptions to the table.

 

[simon mugo]

It all depends on the type of material of the grounding rod. the image below will guide you accordingly. Size 4 for copper and size 2 for aluminium would work better. Check it out here http://wiresizecalculator.net/table....htm?msclkid=ade4e70dba0611ec90fbb867dc467956

 

[tom baker]

It all depends on the type of material of the grounding rod. the image below will guide you accordingly. Size 4 for copper and size 2 for aluminium would work better. Check it out here http://wiresizecalculator.net/table....htm?msclkid=ade4e70dba0611ec90fbb867dc467956

Kind of correct. It’s the type of grounding electrode. See Section 250.66 which includes section A, B, C, and table 250.66

 

[LarryFine]

Size 4 for copper and size 2 for aluminium would work better.

'Ceptin' for the aluminum within 18" of earth.

 

[infinity]

'Ceptin' for the aluminum within 18" of earth.

That pretty much eliminated using Al for a GEC to a ground rod unless the rod is 10' long.

 

[Nitrovoltage001]

So it's a gutter fed with 500 mom and the gutter feed 3 100 amp panels the used taps to go from 500 to #2 and it has only one ground rod with 1/0 copper conductor to it I wanted to add a ground rod but don't wanna use #6

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[augie47]

As long as the Grounding Electrode Conductor is terminated only on ground rod(s) (does not also go to any other electrode), a #6 is the largest you ever need regardless of the service size or the service conductor size.

 

[tom baker]

It all depends on the type of material of the grounding rod. the image below will guide you accordingly. Size 4 for copper and size 2 for aluminium would work better. Check it out here http://wiresizecalculator.net/table....htm?msclkid=ade4e70dba0611ec90fbb867dc467956

That table is for the size of the EGC, not the GEC