![]() ![]() Last edited by Matt Marsh 10-02-2014 at 2:37 PM. To calculate ground wire size, use the Ground Wire Size Calculator. Im trying to understand Section 250. If you run a #6 bare copper GEC, you can run it exposed on the surface unless it is subject to severe physical damage (250.64(B). One of these wires is a ground wire which can be sized down. Grounding rod conductor dimensions for 200amp service. In Table 250.66, it lists a 4 AWG copper grounding conductor for 2/0 copper or 4/0 aluminum service conductors, which are the sizes used for 200A services. Although the minimum size grounding electrode conductor is typically #8 copper for a 100 amp service (it's actually determined by feeder size, not amperage), the NEC requires that conductors smaller than #6 be physically protected (usually conduit). In the NEC, there appears to be two tables that contradict each other in regard to the minimum sized equipment grounding conductor. Ground Wire Size Table Note: View wire size charts from the list below. It is almost always easier and more cost effective to satisfy the NEC requirement by supplementing one ground rod with an additional one (250.53(a)(2). This table lists the minimum sizes of grounding conductors for grounding raceways and equipment. The measurement must be performed with a dedicated ground resistance meter, something that very few contractors have. The only way that you can get by with a single one, is if you can prove by measurement that the ground resistance is 25 ohms or less. Inches : 1.736, Weight lbs./1000ft : 1.166 lbs, Ampacity : Direct burial : 345 Amps, Ampacity : In duct : 265 Amps. The GFCI must handle at least 100 amps of current if your electrical equipment draws 50 amps. ![]() GFCIs should be sized twice as large as the current load. If you are using rod type electrodes, you really need to drive two of them, at a minimum of 6' apart. Specifications : Size AWG : 350, Stranding : 37, Insulation Thickness (mils) : 95, Neutral Size AWG : 4/0, Single Phase Conductor Inches : 0.851, O.D. A 200-amp service requires copper conductors of 4 AWG or aluminum or copper-clad aluminum ground wires of 2 AWG. Neutral lug is bonded to ground bar in 200 A combination panel. From the meter base run 2 black and one white to combination panel with main disconnect. The only exception is if the separate building is fed with just a single branch circuit (2014 NEC 250.32a). Here it is: Scenario 1: Install system grounding conductor in meter base by running properly sized copper wire from ground lug in meter base to ground rods (or ground plate). Generally, a 2/0 copper wire is ideal for a 200-amp service that’s below the ground. Jason, A separate building always requires a grounding electrode system in addition to the equipment grounding conductor that you mention. ![]()
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