Ground Rod To Steel

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Alwayslearningelec

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I have about 20 ground rods around building with 500 mcm ground ring attached to each.
They are showing this detail for 2/0 to steel.
They don't give details whether or not this has to happen at every ground rod.
Any code regarding this? Thanks
 

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The ground ring isn't shown on your detail. Looks like they want each ground rod Cadwelded to a piece of #2/0 to the building steel. A waste of money but the dirt worshipers will sleep better at night.
 
The code does not require any of that....it all becomes a design choice. The only thing the code would require is tying the rods and ground ring together and taking a minimum of a 4 awg copper grounding electrode conductor to the service equipment.
 
don_resqcapt19 said:
The code does not require any of that....it all becomes a design choice. The only thing the code would require is tying the rods and ground ring together and taking a minimum of a 4 awg copper grounding electrode conductor to the service equipment.
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Doesn't the ground ring need #2 back to the panel or can you encircle with #2 and then use #4 to the service? I always assumed it needed to be #2 all the way
 
Dennis Alwon said:
Doesn't the ground ring need #2 back to the panel or can you encircle with #2 and then use #4 to the service? I always assumed it needed to be #2 all the way
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you are correct .... I was thinking of a concrete encased electrode.

In this case, the GEC from the ring will probably have to be per Table 250.66, as I expect this facility has a service much larger than 400 amps.
 
don_resqcapt19 said:
you are correct .... I was thinking of a concrete encased electrode.

In this case, the GEC from the ring will probably have to be per Table 250.66, as I expect this facility has a service much larger than 400 amps.
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Don where does it state that the ring must use 250.66. It says that the ring must consist of not smaller than #2 in the same way that a concrete encase electrode states not smaller than #4.
 
Dennis Alwon said:
Don where does it state that the ring must use 250.66. It says that the ring must consist of not smaller than #2 in the same way that a concrete encase electrode states not smaller than #4.
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Unless you're connecting to other electrodes that require a conductor larger than the ground ring GEC the ring GEC is not required to be larger than the ground ring conductor.

250.66(C) Connections to Ground Rings. If the grounding electrode conductor or bonding jumper connected to a ground ring, as described in 250.52(A)(4), does not extend on to other types of electrodes that require a larger size of conductor, the grounding electrode conductor shall not be required to be larger than the conductor used for the ground ring.
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Dennis Alwon said:
That is my understanding also
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250.66(C) only says the grounding electrode conductor to the ring is not required to be larger than the conductor that is used to create a ring, so if you have a service that requires a 3/0 GEC and the ring is only 2 AWG, the GEC to the ring is permitted to be 2 AWG.

In this case the ground ring is made up of a 500 kcmil, and that is larger than any required grounding electrode conductor, triggering a requirement a table sized grounding electrode conductor.
 
don_resqcapt19 said:
In this case the ground ring is made up of a 500 kcmil, and that is larger than any required grounding electrode conductor, triggering a requirement a table sized grounding electrode conductor.
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I agree, if they used the code minimum of #4 then the GEC would not need to be larger than that. Since it's a 500 kcmil ring then #3/0 from T250.66 would be required.
 
infinity said:
I agree, if they used the code minimum of #4 then the GEC would not need to be larger than that. Since it's a 500 kcmil ring then #3/0 from T250.66 would be required.
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Only if the size of the service conductors would require a 3/0 GEC.
 
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