I just dug one 18" deep trench indigenous the home to mine detached garage and I"m about to run 3-gauge business cable because that my brand-new 100-amp below panel. The garage is only 10 feet far from the house. The cable will certainly be encased in PVC conduit. The main 200-amp business panel in ~ the house is well-grounded, and also a couple of electricians right here in LA have actually told me that i don"t require any added grounding rods because that the sub-panel, simply a eco-friendly grounding wire the will get run ago to the main organization panel.Anybody understand what dimension wire I require for the eco-friendly ground wire? ns think I check out 8 someplace, however I want to be sure.Thanks!- Jason


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Jason, ns would suggest you acquire to understand your regional inspector and ask that what he wants to see. Municipalities don"t have to follow the NEC, or also the recent NEC, yet as much as ns know, the NEC a ground stick (sometimes 2 floor rods) is required for detached structures.
Jason, i would suggest you gain to recognize your neighborhood inspector and also ask him what he wants to see. Municipalities don"t need to follow the NEC, or also the latest NEC, but as much as i know, the NEC a ground pole (sometimes 2 ground rods) is forced for detached structures.
The State that California mandates which password & once it is adopted, currently the 2011 is gift enforced. 250.56 claims if you cannot prove 25 Ohms the resistance or much less then a second one is forced at least 6 feet except the 1st one & the is all the is needed, since the testing tools is high value it"s cheaper & easier to just drive the second rod. A jurisdiction may have stricter regs, yet may not have lesser requirements, so the above quote walk not apply in the State the California.
For a circuit protected by a 100 A breaker, the minimum ground wire size is #8 copper or #6 aluminum.


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Jason, A separate building always requires a ground connection electrode system in enhancement to the tools grounding conductor that you mention. The only exemption is if the separate building is fed with simply a solitary branch circuit (2014 NEC 250.32a). If you room using rod kind electrodes, you really have to drive 2 of them, in ~ a minimum the 6" apart. The only method that you can acquire by through a single one, is if you deserve to prove by measurement that the ground resistance is 25 ohms or less. The measurement have to be performed through a devoted ground resistance meter, something that very couple of contractors have. The is almost always much easier and more cost efficient to fulfill the NEC necessity by supplementing one ground pole with second one (250.53(a)(2). Back the minimum dimension grounding electrode conductor is generally #8 copper because that a 100 amp company (it"s actually established by feeder size, no amperage), the NEC needs that conductors smaller than #6 be physically safeguarded (usually conduit). If you operation a #6 bare copper GEC, you can run that exposed on the surface ar unless that is topic to significant physical damages (250.64(B).