Sizing Grounding Electrode Conductor....

[xformer]

I am of the understanding that to size the EGC, we use 250.66. I am also of the understanding that when i am connecting to a Ground rod that the EGC at the connection point doesnt have to be bigger than #6.

Do I understand correctly or do I understand amiss?

 

[petersonra]

I am of the understanding that to size the EGC, we use 250.66. I am also of the understanding that when i am connecting to a Ground rod that the EGC at the connection point doesnt have to be bigger than #6.

Do I understand correctly or do I understand amiss?

EGC = equipment grounding conductor.

250.66 is indeed where GEC (grounding electrode conductor) sizing is discussed.

Take a look at 250.66 (A), (B), and (C). this covers connections to rods, pipes, plates, CEE, and rings. All other GE have to follow table 250.66.

 

[xformer]

EGC = equipment grounding conductor.

250.66 is indeed where GEC (grounding electrode conductor) sizing is discussed.

Take a look at 250.66 (A), (B), and (C). this covers connections to rods, pipes, plates, CEE, and rings. All other GE have to follow table 250.66.

sorry, I ment the GEC not the EGC....

 

[Dennis Alwon]

I am of the understanding that to size the EGC, we use 250.66. I am also of the understanding that when i am connecting to a Ground rod that the EGC at the connection point doesnt have to be bigger than #6.

Do I understand correctly or do I understand amiss?

You got it for the grounding electrode conductor and 250.66 and the equipment grounding conductor is 250.122. Make sure to read the notes to T. 250.66

 

[infinity]

I am also of the understanding that when i am connecting to a Ground rod that the EGC at the connection point doesnt have to be bigger than #6.

That is correct, unless the GEC is subject to physical damage them a #4 is required.

 

[Cjmcelectric]

The # 6 can only be used on a single ground rod if there isn't the ability to do one the other methods of GE.it is my understanding that you have to use a GEC sized off of 250.66 if you can install more than one. So if you use the ground rod as a supplemental ground it needs to be -example a#4 for 200a service.

 

[jumper]

The # 6 can only be used on a single ground rod if there isn't the ability to do one the other methods of GE.it is my understanding that you have to use a GEC sized off of 250.66 if you can install more than one. So if you use the ground rod as a supplemental ground it needs to be -example a#4 for 200a service.

I do not think this is correct. On what code section do you base this assumption on?

This section is pretty clear to me.

250.66 Size of Alternating-Current Grounding Electrode
Conductor. The size of the grounding electrode conductor
at the service, at each building or structure where
supplied by a feeder(s) or branch circuit(s), or at a separately
derived system of a grounded or ungrounded ac system
shall not be less than given in Table 250.66, except as
permitted in 250.66(A) through (C).


(A) Connections to Rod, Pipe, or Plate Electrodes.
Where the grounding electrode conductor is connected to
rod, pipe, or plate electrodes as permitted in 250.52(A)(5)
or (A)(7), that portion of the conductor that is the sole connection
to the grounding electrode shall not be required to be
larger than 6 AWG copper wire or 4 AWG aluminum wire.

 

[Cjmcelectric]

I did word this right sorry In article 250.66 (a)it says that as long as you run solely to ground rod from service ,it only has to be a #6 but if you were to go to a grounding electrode type such as waterpipe then to your ground rod with one conductor you would need to use a sizing off Table 2 50.66 Sorry I'm still trying to learn how to explain my interpretation of the code better!:dunce:

 

[Dennis Alwon]

I did word this right sorry In article 250.66 (a)it says that as long as you run solely to ground rod from service ,it only has to be a #6 but if you were to go to a grounding electrode type such as waterpipe then to your ground rod with one conductor you would need to use a sizing off Table 2 50.66 Sorry I'm still trying to learn how to explain my interpretation of the code better!:dunce:

The wording stinks as that was exactly what I said to the cmp regarding this issue. They assured me that 2 rods with a #6 was compliant but the wording does not support that. I wrote a proposal on that and I believe it was accepted. I;ll check

 

[Dennis Alwon]

Here is the draft-- basically the same as I proposed but this was more inclusive

(A) Connections to Rod, Pipe, or Plate Electrode(s).
Where the grounding electrode conductor is connected to a
single, or multiple rod, pipe, or plate electrode(s) or any
combination thereof as permitted in 250.52(5) or (A)(7),
that portion of the conductor that is the sole connection to
the grounding electrode(s) shall not be required to be larger
than 6 AWG copper wire or 4 AWG aluminum wire. [ROP
5?131]

 

[infinity]

Basically nothing has changed, the accepted proposal is clerical change that now uses the singular word, electrode or the plural, electrodes.