The conductor that connects the grounded neutral conductor at service equipment, the building or structure disconnecting means enclosure, or a separately derived systems enclosure to an electrode (earth). A device that establishes an electrical connection to the earth. The conductor that connects equipment to the earth via a grounding electrode.Īuthor’s comment: An example would be the conductor used to connect equipment to a supplementary grounding electrode. The conductor that terminates to the terminal that is intentionally grounded to the earth. ![]() A ground-fault current path is simply all of the available conductive paths over which fault current flows on its return to the electrical supply source during a ground fault. The difference between an “effective ground-fault current path” and “fault-current path” is that the effective ground-fault current path is “intentionally” constructed to provide the low-impedance fault-current path to the electrical supply source for the purpose of clearing the ground fault. An electrically conductive path from a ground fault to the electrical supply source.Īuthor’s comment: The fault-current path of a ground fault is not to the earth! It’s to the electrical supply source, typically the XO terminal of a transformer. An unintentional connection between an ungrounded conductor and metal parts of enclosures, raceways, or equipment. Earth or a conductive body that is connected to earth. Fault current returns to the power supply (source), not the earth! Refer to 250.118 for acceptable types of equipment grounding conductors. The low-impedance fault-current path used to bond metal parts of electrical equipment, raceways, and enclosures to the effective ground-fault current path at service equipment or the source of a separately derived system.Īuthor’s comment: The purpose of the equipment grounding (bonding) conductor is to provide the low-impedance fault-current path to the electrical supply source to facilitate the operation of circuit overcurrent protection devices in order to remove dangerous ground-fault voltage on conductive parts. The effective ground-fault current path is intended to help remove dangerous voltage from a ground fault by opening the circuit overcurrent protective device.Įquipment grounding conductor. An intentionally constructed, permanent, low-impedance conductive path designed to carry fault current from the point of a ground fault on a wiring system to the electrical supply source. A conductor properly sized in accordance with Article 250 that ensures electrical conductivity between metal parts of the electrical installation.Įffective ground-fault current path. ![]() The permanent joining of metal parts together to form an electrically conductive path that has the capacity to conduct safely any fault current likely to be imposed on it.Īuthor’s comment: Bonding is accomplished by the use of conductors, metallic raceways, connectors, couplings, metallic-sheathed cables with fittings, and other devices recognized for this purpose. ![]() So let’s review a few important definitions contained in Articles 100 and 250.īonding. Why is grounding so difficult to understand? One reason is because many do not understand the definition of many important terms.
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