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Continued from question, do I have to go from meter/main combo to the 2 ground rods ,then back inside connect to outside part of my copper water line,then back to the existing 100amp main breaker box, that will become a sub panel in one continuous, unbroken run to achieve proper grounding. The reason I am putting in the 200amp meter/main panel is because the 100amp entrance cable you can see the ground wire through the covering and the meter hub bottom is rusted out. So I'm upgrading to the 200amp combo which will provide a outside main disconnect also. Can I use some of the open spots on the outside panel and run circuits to the in side of the house because the 100amp panel is maxed out.

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  • If you have an interior main breaker, then you can make either panel the "main panel" for bonding purposes. If you choose the inner, mark the outer "Emergency Disconnect Only - Not A Service Disconnect" or something like that. Dec 5, 2023 at 23:03

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A few different pieces here:

  • Ground wire from main panel to ground rods. This is one wire, no breaks/splices.
  • Ground wire from main panel to copper water pipe. Many jurisdictions no longer require this, or may only require one ground rod if you are able to ground to the copper water pipe. Varies a lot - worth checking in advance to find out what they expect. If you do need to run a ground wire to the water pipe then (a) it should connect to the water pipe between where it enters your house (within 5') and the first shutoff valve and (b) it is a different wire from the wire to the ground rods.
  • Ground wire from main panel to subpanel. This is run together with the two hot wires and the neutral wire, either as 4 wires together in a conduit or as a cable. This is a different wire from the wire to the ground rods and from the wire (if you need it) to the water pipe.
  • Yes, you can use other breakers in the outside meter main to run other loads or connect additional subpanels. That is what they are for.

And last, but not least, you need to move all ground wires in your old-main-that-is-now-a-subpanel to the ground bar (add another ground bar if you need to) and remove the neutral-ground bond.

When this is all done, the outside is your only main panel. So that is the only place that needs the special ground wires and the only place with a neutral-ground bond.

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  • Note the "first shutoff valve" is sometimes very far from the entrance. NEC requires bonding within 5 ft of the service entrance. Dec 4, 2023 at 8:54
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    @RobertChapin I was thinking more about the opposite problem - shutoff 1' from entrance but bond put on the inside which is then subject to problems if valve is replaced and not conductive. Dec 4, 2023 at 15:30
  • You’re completely forgetting the point of bonding household water pipes: to ensure that if a live wire touches and electrifies them, it causes a fault that trips a breaker/blows a fuse before it can kill someone. This is entirely distinct from using water supply piping as a local grounding rod. Having “real” ground rods never eliminates the need to bond metal pipes.
    – nobody
    Dec 6, 2023 at 3:32
  • @nobody Citation needed Dec 6, 2023 at 3:37

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