Jeffery asks us: When a residential service is replaced in areas without city water systems, plastic well water line, and ground rods are all that is available, does the requirement change for only a # 6 copper conductor to the rods, being it is now primary gounding electrode and not supllimental. ( say larger home 120/240V, 400(320) Amp?
Thank you for your question regarding residential grounding, it is our pleasure to help.
The latest National Electrical Code has recently made some changes to the grounding requirements for homes. You are now required to install two (2) 10-ft ground rods at least 6-ft apart, even if you have a copper water main. E&S Grounding recommends a 20-ft spacing between these rods.
There are a few exceptions to this rule. If you can test for resistance-to-ground and can demonstrate that one (1) ground rod by itself is under 25 ohms, you don’t need the second rod. Also, if you are willing to dig 18-inch deep holes and completely bury your ground rods, you can use 8-ft rods (you must use connections rated for direct burial).
Keep in mind, you still MUST bond to the steel rebar in the foundation, the gas main, the water main, the cable entrance, the telco ground, any lightning protection system, your swimming pool ground, and any other ground system, just as before. It is just that you may not count these as grounding electrodes anymore.
We hope this helps. Good luck!
The Engineering Team at E&S Grounding Solutions