Inspector wants 2 ground rods

[animal12]

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

 

[Dennis Alwon]

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)

 

[curt swartz]

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.

 

[infinity]

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.

Yup, his sub would need a maximum of a 90 amp feeder OCPD.

 

[bwat]

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

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.

 

[infinity]

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.

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.

 

[LarryFine]

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.

 

[GoldDigger]

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.

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

 

[texie]

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.

Good question. I have never seen a meter/main that did not have permanent factory bonding.

 

[bwat]

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.

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.

 

[tom baker]

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

If you run in the feeder raceway be aware of the special bonding for a GEC in a metallic raceway

 

[kwired]

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.

 

[norcal]

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.

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