sub-panel ground rod

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uwireme

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Cottonwood, CA
I looked at a older home with a meter main outside a large sub-panel in garage and a second sub-panel on the opposite wall in the garage. The meter has a ground rod and a 4 wire going to the large sub panel, the second sub panel in the same garage only has a 3 wire feed and put in another ground rod. The neutrals and grounds were separated with the rod on the ground side. Should I disconnect the ground rod and combine the neutrals and grounds? I know the best thing would be is to install a egc, but she has no money.
 
The small subpanel is getting two hots and a neutral from the larger panel, and the only things on the ground bus are branch circuit ground leads and a rod. Right?

Think of the fault current paths and that dirt is not a good conductor.

First thing is you need to bond all of the rods together. That should give you an effective, but not a legal, fault current path.

Second, you really need to turn the 3-wire feeder into a 4-wire; that shouldn't cost much. (Was the small sub originally the service panel? If it's N's and G's were combined and the panel was old enough, it might be grandfathered, but I wouldn't count on that.)
 
Yes the grounds and rod are connected together and bonded to can. Neutrals are isolated

Couldn't I just take the second rod out and connect all neutrals and grounds together?
 
I think back in the 60s when this was installed they ran a 3 wire feeder then later installed a ground rod and separated the neutrals and grounds. I thought it would be best to connect them all together due to the rod would not clear a fault. But the home inspector did not like that, he wants them separated. Now I am thinking to remove the rod and bring it back to the way it was everything together.
 
As far back as I can find it was never code compliant to use a 3 wire feeder to supply a sub panel in the same building as the service. The allowance to use a 3 wire feeder was only for separate building or structures. I have NEC's going as far back as 1925.
 
uwireme said:
I think back in the 60s when this was installed they ran a 3 wire feeder then later installed a ground rod and separated the neutrals and grounds. I thought it would be best to connect them all together due to the rod would not clear a fault. But the home inspector did not like that, he wants them separated. Now I am thinking to remove the rod and bring it back to the way it was everything together.
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What's the wiring method for the feeder? Is it a cable?
 
packersparky said:
As far back as I can find it was never code compliant to use a 3 wire feeder to supply a sub panel in the same building as the service. The allowance to use a 3 wire feeder was only for separate building or structures. I have NEC's going as far back as 1925.
Click to expand...

I wonder what the reasoning was to allow three wire at a separate structure but not the same structure?

I see this a lot but usually the branch circuits on a 3 wire feeder don't have grounds and there is not another ground rod
 
uwireme said:
I wonder what the reasoning was to allow three wire at a separate structure but not the same structure?

I see this a lot but usually the branch circuits on a 3 wire feeder don't have grounds and there is not another ground rod
Click to expand...

It is less likely to have parallel paths between panels when installed between separate structures than it is when installed in the same structure.
 
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