Grounding Electrode Conductor Size

[TrvTim]

What size ground would you use for a 600 amp service fed with parallel 300's?

 

[LarryFine]

Welcome to the forum!

What size ground would you use for a 600 amp service fed with parallel 300's?

For which electrode?

 

[iwire]

AL or CU?

What kind of electrode?

 

[lakee911]

I'm assuming he is referring to requirements listed in 250.66, no?

 

[TrvTim]

Cu.

Yes I am referring to the requirements listed in 250.66.

I just wanted to check my math before I installed as I am running 300's in parrallel.

 

[TrvTim]

I am trying to size the grounding electrode.

 

[don_resqcapt19]

Tell us what size you think that the code requires for your application and we will tell you if you are correct. Also tell us what is being used as the grounding electrode.

 

[iwire]

Tim we are asking what kind of electrode (Rod, water pipe, building steel, etc) as it makes a difference in the answer.

If you running the GEC to a rod it could be just 6 AWG copper.

If it's the water line it will be much larger.

 

[TrvTim]

It is the water pipe ground.

 

[George Stolz]

2 sets for 570A, or three sets for 855?

 

[TrvTim]

Explain the sizing

 

[Dennis Alwon]

Explain the sizing

I believe George is referring to article 240.4(B) where you can use 570 amps for a six hundred amp service if the calculated load is not greater than 570.

So are you using 2 sets of 300 or 3 sets is the question?

 

[TrvTim]

We are using 2 sets of 300mcm.

 

[Dennis Alwon]

We are using 2 sets of 300mcm.

Have you come up with an answer. Use note #1 to Table 250.66

 

[TrvTim]

i came up with a 1/0. I just wanted to see if anyone else came up with something different.