Inspector wants 2 ground rods

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animal12

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howdy folks , I have a job where we are going to turn the meter main panel into a sub panel , it's 100 A & feed it from a new 200 A service , we installed a ground rod because the HO didn't want us to disturb her pavers where the existing ground rod is . we will be feeding the soon to be 100 sub with 3 # 4 & i # 8 copper thhn , & installing a separate ground bar in the panel . the inspector showed up today & said we need 2 ground rods 6' apart due to the fact that there is no ufer ground for the new 200 service . what am I missing ? Im in northern Calif
tks
animal
 
What you are missing is the second ground rod. The code requires 2 rods or some other form of electrode if you cannot reach 25 ohms with one rod. This has been in the code for a long time but many areas overlooked it. Look at 250.53(A)(2)
 
Your #4's are also too small for a 100 amp feeder if you are feeding any other loads from the 200 amp service panel.
 
animal12 said:
howdy folks , I have a job where we are going to turn the meter main panel into a sub panel , it's 100 A & feed it from a new 200 A service , we installed a ground rod because the HO didn't want us to disturb her pavers where the existing ground rod is . we will be feeding the soon to be 100 sub with 3 # 4 & i # 8 copper thhn , & installing a separate ground bar in the panel . the inspector showed up today & said we need 2 ground rods 6' apart due to the fact that there is no ufer ground for the new 200 service . what am I missing ? Im in northern Calif
tks
animal
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Is the sub in the same building as the new main? Confused by the bolded part. Sounds like you already have 2 rods. Or else I didn’t understand the intent of the comment.
 
bwat said:
Is the sub in the same building as the new main? Confused by the bolded part. Sounds like you already have 2 rods. Or else I didn’t understand the intent of the comment.
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I'm guessing that the old rod was abandoned due to be in an area where it was inaccessible. But you are correct if they can access the old GEC from that existing rod then they will have the two rods required.
 
How do you properly use a meter-main as a sub-panel? First issue is rewiring an assembly like adding an ATS would require. Second is isolating grounds and neutrals.
 
bwat said:
Is the sub in the same building as the new main? Confused by the bolded part. Sounds like you already have 2 rods. Or else I didn’t understand the intent of the comment.
Click to expand...
I think it would be compliant to run a GEC (continuous, of course) from the old panel sure to the new service entrance. But if you cannot directly access the original electrodes you might have to make an irreversible connection to the old GEC instead. It is good practice to keep the GEC short, but not required by code.

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LarryFine said:
How do you properly use a meter-main as a sub-panel? First issue is rewiring an assembly like adding an ATS would require. Second is isolating grounds and neutrals.
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Good question. I have never seen a meter/main that did not have permanent factory bonding.
 
infinity said:
I'm guessing that the old rod was abandoned due to be in an area where it was inaccessible. But you are correct if they can access the old GEC from that existing rod then they will have the two rods required.
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Yes, it may end up to be better/easier to just drive another rod, but I wanted to point out that there may be another option here. Good additional info from GoldDigger as well on GEC connections.
 
GoldDigger said:
I think it would be compliant to run a GEC (continuous, of course) from the old panel sure to the new service entrance. But if you cannot directly access the original electrodes you might have to make an irreversible connection to the old GEC instead. It is good practice to keep the GEC short, but not required by code.

Sent from my XT1585 using Tapatalk
Click to expand...

If you run in the feeder raceway be aware of the special bonding for a GEC in a metallic raceway
 
Probably cost less to use a second rod at the new service than to run a new conductor to the old rod, and then if not disturbing the pavers over it to have to make a proper splice as well.
 
LarryFine said:
How do you properly use a meter-main as a sub-panel? First issue is rewiring an assembly like adding an ATS would require. Second is isolating grounds and neutrals.
Click to expand...

Most are listed for use only as service equipment, so it is a no go.
 
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