I just dug an 18" deep trench from the home to my detached garage and I"m around to run 3-gauge company cable for my new 100-amp sub panel. The garage is just 10 feet far from the house. The cable will certainly be encased in PVC conduit. The main 200-amp service panel at the home is well-grounded, and also a pair of electricians here in LA have actually told me that i don"t require any extr grounding rods for the sub-panel, simply a green grounding wire the will obtain run ago to the main business panel.Anybody know what size wire I need for the environment-friendly ground wire? ns think I check out 8 someplace, however I want to it is in sure.Thanks!- Jason

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Jason, ns would indicate you gain to understand your regional inspector and also ask the what he wants to see. Municipalities don"t need to follow the NEC, or even the recent NEC, however as much as i know, the NEC a ground stick (sometimes 2 soil rods) is forced for detached structures.
Jason, i would suggest you get to know your neighborhood inspector and ask him what he desires to see. Municipalities don"t have to follow the NEC, or also the latest NEC, however as far as ns know, the NEC a ground stick (sometimes 2 soil rods) is forced for detached structures.
The State that California mandates which password & when it is adopted, right now the 2011 is being enforced. 250.56 states if you cannot prove 25 Ohms the resistance or much less then a 2nd one is required at least 6 feet except the 1st one & the is all that is needed, since the testing tools is expensive it"s cheaper & less complicated to simply drive the second rod. A jurisdiction may have actually stricter regs, but may not have lesser requirements, therefore the above quote go not apply in the State of California.
For a circuit safeguarded by a 100 A breaker, the minimum ground wire size is #8 copper or #6 aluminum.

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Jason, A different building always requires a ground connection electrode mechanism in addition to the devices grounding conductor that you mention. The only exemption is if the separate structure is fed with just a solitary branch circuit (2014 NEC 250.32a). If you are using rod kind electrodes, you really should drive 2 of them, at a minimum the 6" apart. The only method that girlfriend can get by v a single one, is if you can prove by measurement that the floor resistance is 25 ohms or less. The measurement have to be performed through a dedicated ground resistance meter, something that very couple of contractors have. The is almost always much easier and an ext cost effective to satisfy the NEC necessity by supplementing one ground pole with secondary one (250.53(a)(2). Back the minimum size grounding electrode conductor is typically #8 copper for a 100 amp company (it"s actually figured out by feeder size, no amperage), the NEC needs that conductors smaller than #6 be physically defended (usually conduit). If you operation a #6 ceiling copper GEC, you deserve to run it exposed on the surface unless it is topic to major physical damages (250.64(B).