Course Content
NEC Chapter 3 Wiring Methods & Materials
About Lesson

Grounding and bonding are essential components of electrical systems, and they ensure that the system is safe, reliable, and protected against electrical faults. The National Electrical Code (NEC) specifies the requirements for grounding and bonding of wiring methods, which must be followed during installation and maintenance. In this lesson, we will discuss the requirements for grounding and bonding of wiring methods.

  1. Grounding: Grounding provides a low-impedance path for fault currents to flow to the earth, which prevents the buildup of voltage and reduces the risk of electrical shock or fire. The grounding system must be connected to a grounding electrode, which is a conductor buried in the earth that provides a low-impedance path for fault currents. All electrical equipment and wiring methods must be grounded according to the NEC requirements.

  2. Bonding: Bonding is the process of connecting all metallic components of the electrical system to form a continuous path for fault currents to flow. The bonding system must be connected to the grounding system to ensure that all metallic components are at the same potential and that any fault current can flow to the earth. The bonding conductor must be sized according to the NEC requirements, and it must be connected to all metallic components of the system, including equipment enclosures, conduit, raceways, and other metallic components.

  3. Equipment Grounding Conductor (EGC): The EGC is a conductor that is used to connect the equipment enclosure to the grounding system. The EGC provides a low-impedance path for fault currents to flow to the earth, which protects the equipment from damage and prevents electrical shock or fire. The EGC must be sized according to the NEC requirements, and it must be connected to the equipment enclosure and to the grounding system.

  4. Separately Derived Systems: Separately derived systems are electrical systems that are not connected to the primary source of power. Examples include generators and transformers. These systems must be grounded and bonded according to the NEC requirements, which specify the size of the grounding electrode conductor and the bonding conductor.

  5. Ground Fault Circuit Interrupters (GFCI): GFCIs are devices that protect against electrical shock by interrupting the flow of current when a fault is detected. GFCIs must be installed in locations where electrical equipment is used near water, such as bathrooms, kitchens, and swimming pools. The NEC specifies the requirements for GFCI installation, which must be followed during installation and maintenance.

In summary, grounding and bonding are essential components of electrical systems, and they ensure that the system is safe, reliable, and protected against electrical faults. The requirements for grounding and bonding of wiring methods include connecting the grounding system to a grounding electrode, bonding all metallic components of the system, using the EGC to connect the equipment enclosure to the grounding system, following the NEC requirements for separately derived systems, and installing GFCIs in locations where electrical equipment is used near water. It is important to follow these requirements to ensure that electrical systems are safe and compliant with the NEC.

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