320 meter base install

[airemdwn]

I will be installing a 320 meter base with double lugs on the outside of a 3500sq.ft. Ranch house. I will be installing a 200 amp main breaker panel via 4/0 SE Cable in the basement under the Meterbase and a 200 amp Disconnect via 4/0 Se cable next to the panel. The disconnect will feed a subpanel closer to the kitchenvia 4/0 ser cable(copper costs).

The house is well water, I do not remember any provisions in the 320 meterbase for bonding to the Grounding electrode conductor, So will a no. 4 awg from the panel and disconnect to 2 ground rods be sufficient according to the 2005 code? Should it be a 1/0 from both or a 1/0 from the gr.rods and no.4 bugged from the panel and dis. to derive my ground electrode system?
Thanks for any thoughts.

 

[suemarkp]

All a ground rod ever needs is a #6 copper, so pick a panel (the disconnect or the basement panel) and run a #6 or larger GEC to the rods. As long as the neutral in the 4/0 SE is equivalent to 3/0 Al or larger, then that can ground all your service equipment and no other wire or GEC taps are required.

Do you have any metallic water piping that needs to be bonded? If so, that may need 1/0 copper or 3/0 aluminum. The exact size depends on the size of your SEC's (you may be able to move up one row in 250.66). I didn't do the math for two 4/0's, and you didn't say if there was a set of larger wires feeding the meter. Whatever size is correct, I'd run it from the same panel you connect your GEC's to, but I think you could choose either panel if you really want to.

 

[infinity]

Grounding issues aside you may have a problem with the disconnect on the outside and the panelboard on the inside. This would give you two service disconnects which are required to be grouped together. The disconnect would need to be installed on the inside next to the panel or a separate disconnect for the panel would need to be installed on the outside so that they two are grouped together. Look at 230.70(A).

 

[infinity]

Grounding issues aside you may have a problem with the disconnect on the outside and the panelboard on the inside. This would give you two service disconnects which are required to be grouped together. The disconnect would need to be installed on the inside next to the panel or a separate disconnect for the panel would need to be installed on the outside so that they two are grouped together. Look at 230.70(A).

This is what happens when you post a 4:55 am. I misunderstood your OP. For some reason I thought that the disco was on the outside. Forget about my first post.

 

[hardworkingstiff]

This is what happens when you post a 4:55 am. I misunderstood your OP. For some reason I thought that the disco was on the outside. Forget about my first post.

I did the same thing.

 

[LarryFine]

You guys are forgiven.

I would think that a single #6 would suffice for both panels to both rods, as long as the conductor is unbroken. I also run two independent #4's, one for each panel, to the water pipe if it's nearby. I've it this way several times, and it's never been an issue.

 

[Lady Engineer]

Question: Does the #6 only apply if the ground rod is the not the first connection to system grounding, i.e. like first connecting to the building steel, then the ground rod? It kind of insinuates that in the handbook.

What's your take?


Lady

 

[raider1]

Does the #6 only apply if the ground rod is the not the first connection to system grounding, i.e. like first connecting to the building steel, then the ground rod?

250.66(A) Only applys to "that portion of the conductor that is the sole connection to the grounding electrode...."

So if you are going to connect to a ground rod and then connect from the ground rod to the building steel or water pipe ect.. you must size the grounding electrode conductor according to Table 250.66. But if you only have one wire running to the ground rod it only has to be a #6 copper conductor.

Chris

 

[Lady Engineer]

that's what I thought...thanks.


Lady

 

[raider1]

You are very welcome.

Chris

 

[ironman55]

I will be installing a 320 meter base with double lugs on the outside of a 3500sq.ft. Ranch house. I will be installing a 200 amp main breaker panel via 4/0 SE Cable in the basement under the Meterbase and a 200 amp Disconnect via 4/0 Se cable next to the panel. The disconnect will feed a subpanel closer to the kitchenvia 4/0 ser cable(copper costs).

The house is well water, I do not remember any provisions in the 320 meterbase for bonding to the Grounding electrode conductor, So will a no. 4 awg from the panel and disconnect to 2 ground rods be sufficient according to the 2005 code? Should it be a 1/0 from both or a 1/0 from the gr.rods and no.4 bugged from the panel and dis. to derive my ground electrode system?
Thanks for any thoughts.

I would use a solid #6 from gnd rod to meter-can from meter-can to servs pnl. then a stranded #8 from gnd rod straght to servs pnl. for a dubble gnd system. (For wire sizes depends on voltige drop "if any" )2-2/0 1-1/0 and a #1 for a 4 wire system

 

[ironman55]

You guys are forgiven.

I would think that a single #6 would suffice for both panels to both rods, as long as the conductor is unbroken. I also run two independent #4's, one for each panel, to the water pipe if it's nearby. I've it this way several times, and it's never been an issue.

(dubble-grounding is good)