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The main panel has a neutral and three ungrounded conductors entering it from the utility provider is also has a grounding rod the neutral and three conductors get transmitted from one location to the other location into a sub panel in the sub panel it has a neutral bus and a grounding bus the grounding bus is isolated and every possible way from the neutral bus is this bad.

I know a little bit about electricity and I didn't do this project I'm just wondering because I know and a main panel all the grounds and neutrals come together in the main bus, and when it goes to a sub panel the grounds and neutrals are isolated from the main panel out, and go to separate buses.

I'm just wondering if the main grounding bus in the side panel has to be bonded to the main neutral bus in the main panel with a wire or a grounding rod is sufficient.

I know if the ground is not probability bonded to a neutral it could probably store electricity in if someone touches it could deliver a fatal electrocution.

Note: I know electricity is not stored it just flow along it. But if it's a capacitor it will store electricity

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Short answer, you do want a ground conductor between the main panel and subpanel (not just a ground rod at the subpanel) and you only want the neutral bonded to the ground at the main panel.

The ground rod alone is not sufficient - although there would be a path through ground back to the main building's ground, that is not a low impedance path, it wouldn't be low enough to clear a fault, not safe, etc.

The ground conductor could be a metal conduit from panel to panel provided it's installed properly so that it creates a continuous path back to the main panel.

  • Yes I know that but what I'm trying to say is the ground bus in the sub panel just has a rod going to the earth and is not attached to the neutral in the main panel with a wire. – Furjon Dec 31 '15 at 8:53
  • Thank you for your answer that's what I thought. the inspector who inspected it had passed it. He said since the main panel and the side panel. Ground ground rods that they would talk to each other through the earth, but I thought that only could occur at much higher voltage not at the lower voltages 120 208 why and 480 volts have you. – Furjon Dec 31 '15 at 9:01
  • I thought it was good practice to run a grounding wire to every grounding bust and you should have at least one grounding rod for the main panel and forever building I know circumstances you have to put in 2 or more – Furjon Dec 31 '15 at 9:05
  • @Furjon, it is downright scary that an inspector would have said this. He is 100% WRONG!! A ground rod and the earth have NOTHING to do with equipment grounds, which is what we are talking about here. The earth IS NOT meant to be used as a path for fault current, this is clearly stated in the NEC (and I'm sure whatever code you are under as well). An equipment grounding conductor MUST be run between a service panel and a non-service panel (sub-panel). PERIOD. – Speedy Petey Dec 31 '15 at 13:30
  • This is why we need to get the wording changed in the NEC to differentiate between grounding electrodes and equipment grounds. Both being called "grounds" is extremely misleading, even to inspectors obviously. – Speedy Petey Dec 31 '15 at 13:32

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