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I have a 100 amp service running from meter base to new garage, that's completely wired.

Now, I'm going to run from garage to new house under construction. I want to use another one hundred amp panel with main breaker. The Inspector said to run 3 conductors with bonding wire to house, this will eliminate having to add ground rods. I know red and black go to main breaker, white to common.

Here is the question, where do I run the bond wire to?

I know I'll have to run a 6 gauge to gas line, but the bond wire has me confused.

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    Where in the world are you, and is this an attached or a detached garage? – ThreePhaseEel Jun 24 '16 at 22:16
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    In the USA (see @ThreePhaseEel's question about where in the world are you), the sub panel will have separate ground and neutral buss bars--- that is different than the main panel, where both neutral and ground use the same buss bar. See: smg.photobucket.com/user/Linesman/media/Electrical/… – Tyson Jun 25 '16 at 1:19
  • Sorry for the slow reply. In Alberta Canada – Grumpyold Jun 25 '16 at 15:35
  • Two separate structures. – Grumpyold Jun 25 '16 at 20:19
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If the house is detached you still need ground rods or a concrete encased electrode. You didn't answer ThreePhaseEel's second question.

Either way, The ground wire gets attached to the ground bar. All grounds and neutrals are kept separate on their own bars. The green bonding screw for the panel is NOT installed. Discard it.

There are several other questions on this site regarding sub-panel installation. Like here.

Good luck!

  • As per local inspector, no ground rods needed if I use the bond wire to carry back to panel in garage and attach in panel so that both panels use the same ground rods. Just not sure where that bond wire needs to be attached in panel in house panel.. – Grumpyold Jun 25 '16 at 15:42
  • The equipment grounding conductor (what you are calling the bond wire) terminates on the ground bar or to a lug attached to the sub-panel. – ArchonOSX Jun 26 '16 at 10:09
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Having the main panel in the garage and a subpanel in the house is the reverse of what's usually done, but should work OK if the inspector will OK it. The panel you install in the house should have ground buss bars and neutral buss bars. Your ground wire from the garage panel gets bonded to one of the positions on the ground buss bar in the house panel.

If the house panel is a new panel with a main breaker you've just bought, then it will have a metal strap connecting the neutral buss bar to the panel box. You should remove an discard this metal strap.

If the house panel is a subpanel with no main breaker, it likely does not have the neutral to ground bonding strap, so should already be configured correctly.

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First -- remove and discard the green bonding strap or screw -- it is not used when configuring the panel as a subpanel. The feeder ground (bond) wire is attached to the main (garage) panel's ground or combination bus and to the ground bus on the subpanel, while the feeder neutral wire lands on the subpanel's neutral bus, which is separate.

Second -- since the garage and house are separate structures, the NEC requires that the house have its own ground electrode, bonded to the ground buss in the subpanel. Either the Canadians did not adopt this requirement for the CEC, or your inspector is strange. Despite that, I would install a ground rod for the house anyway as having no earthing at the service/feeder entrance means you are unprotected from common-mode rise on the service drop or outdoor feeder due to nearby lightning strikes.

  • I have the cable already which is three conductors and a bond but I'm starting to think I should do ground rods at the house and forget the bond wire. If I go this route would the bonding screw still have to be removed, or is it left in place? – Grumpyold Jun 26 '16 at 16:46
  • @Grumpyold -- you need both the bond wire in the cable and the rods at the house. And remove the bonding screw. – ThreePhaseEel Jun 26 '16 at 16:53

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