Bonding of electrical panels is a requirement set forth by the National Electrical Code (NEC). The NEC is responsible for regulation of all electrical installations. Bonding is the permanent joining of all metallic parts in an electrical system. This joining forms a continuous electrical path. It ensures that any errant electrical power will be safely conducted back to the ground. Typically, the bonding of electrical panels is performed by the installation of a single bare copper wire or a green insulated wire that is connected to an exterior ground rod.
Things You'll Need
- Ground rod
- 5-pound hammer
- Ground rod clamp
- Grounding conductor (size depends on panel amperage)
Install the ground rod at the point of entry for your electrical system. The point of entry will be where the main electrical wires enter the home. The ground rod is generally positioned under the home’s utility power meter.
Drive the metal ground rod into the soil using a 5-pound hammer. Leave less than 6 inches exposed above ground level. The ground rod must be driven to its full depth in order to be effective and configure to NEC standards. Typical length of the ground rod is either 6 feet or 8 feet long, depending on local regulations and size of the electrical system.
Place the ground clamp at the top of the driven ground rod. Tighten the clamp with the screwdriver. Make sure the flow of electricity of suspended for the following steps.
Attach the grounding conductor into the wire connector of the ground clamp. Secure the wire with the provided setscrew.
Run the grounding conductor from the ground rod clamp into the main panel. Attach the end of the wire into the solid grounding bar mounted to the rear of the electrical panel. This bar will be electrically and mechanically tied to the metal enclosure of the panel box.
Secure another ground wire from the grounding bar in the first panel box, and run it to the second electrical panel in the electrical wiring system. This bonding wire must be looped to every electrical panel in the system. The wire’s capacity for the grounding conductor must be of the correct size for the electrical panel it is attached to. See Tips and consult Article 250 of the NEC. Some local regulations may require that the bonding wire be placed in some form of protection. In other words, the bonding wire may have to be enclosed by a piece of electrical conduit for its entire length.
Tips & Warnings
- Grounding conductors run in various sizes. These wire sizes depend on the amperage of the panel. According to the NEC Table 250-95, the following wire sizes correspond to amperage like this: Electrical panels rated for 60 amperes or less must use a No. 6 wire. Panels rated from 61 amperes up to 100 amperes must use a No. 8 wire. Panels rated for 101 amperes up to 200 amperes need a No. 6 grounding wire. Panels rated for 201 amperes to 300 amperes will use a No. 4 wire.
- Follow all local electrical codes when installing or servicing any electrical devices. Local regulations may supersede those presented in the NEC book.
- Consult a local licensed electrician if you are unsure of the local regulations or you feel uncomfortable performing any work yourself.
- National Electrical Code; National Fire protection Association; 2002
- Inspectapedia.com: Electrical Ground Inspection
- Photo Credit Jupiterimages/Photos.com/Getty Images
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