#CONCRETE ENCASED ELECTRODE CODE#
#CONCRETE ENCASED ELECTRODE SERIES#

A grounding electrode conductor is run from the service enclosure to one of the grounding electrodes that are bonded together. The general requirement is that a bonding jumper must be installed between the grounding electrodes to bond them together. This includes metal underground water pipes, metal frames of buildings, concrete-encased electrodes, and ground rings. The NEC in Section 250-50 requires that, where available on the premises at each building or structure served, all grounding electrodes including “made” electrodes be bonded together to form the grounding electrode system. The conductor used to make this connection is the grounding electrode conductor. In Section 250-24(c), we find a requirement to connect the equipment grounding conductors, the service-equipment enclosures, and where the system is grounded, the grounded service conductor to a grounding electrode. Over-voltages can also be caused from lightning. These over-voltages can be caused by high-voltage conductors being accidentally connected to the lower-voltage system such as by a failure in a transformer or by an overhead conductor dropping on the lower-voltage conductor. In both situations, the primary purpose of the grounding electrode is to maintain the electrical equipment at the earth potential present at the grounding electrode.Īnother essential function of the grounding electrode is to dissipate over-voltages into the earth. In other instances, the electrode is used to connect noncurrent carrying metallic portions of electrical equipment to the earth. In some cases, the grounding electrode serves to ground the electrical system. The earth is considered to be at zero potential. įor many applications, grounding electrodes provide the essential function of connecting the electrical system to the earth.

This type of grounding electrode generally offers the lowest ground resistance for the cost.A conducting element used to connect electrical systems and/or equipment to the earth.

#CONCRETE ENCASED ELECTRODE SERIES#

The desert site was a series of bomb storage vaults in the area of Flagstaff, Ariz. Ufer came up with was necessary because the site needing grounding had no underground water table and little rainfall. The concrete-encased grounding electrode is also called a 'Ufer Ground,' named after a consultant working for the U.S. The grounding electrode conductor to a concrete-encased grounding electrode isn't required to be larger than 4 AWG copper. If multiple concrete-encased electrodes are present at a building/structure, only one is required to serve as a grounding electrode.Ĭoncrete containing insulation, vapor barriers, films, or similar items separating it from the earth isn't considered to be in 'direct contact' with the earth.

of concrete located horizontally near the bottom of a concrete footing or vertically within a concrete foundation that’s in direct contact with the earth. The reinforcing bars or bare copper conductor must be encased by at least 2 in. diameter, mechanically connected together by steel tie wires, welding, or other effective means, to create a 20 ft or greater length.Ģ) Bare copper conductor not smaller than 4 AWG. A concrete-encased electrode must consist of at least 20 ft of either of the following, as shown in the Figure:ġ) One or more of bare, zinc-galvanized, or otherwise electrically conductive steel reinforcing bars of not less than ½ in.

#CONCRETE ENCASED ELECTRODE CODE#

What are the Code requirements for a concrete-encased electrode?Ī.

Concrete encased electrode