What Is an Earthing Rod?

Purpose

• An earthing rod provides a means to ground electrical wires when no other means are possible. The homeowner installs the earthing rod outside with wires leading to the metal structure. Metal structures that need to have grounding rods include television antennas, satellite dishes and electrical fences for livestock. Depending on the type of structure, the homeowner may install two grounding rods.

Specifications

• Manufacturers create grounding rods from galvanized, copper-plated or solid copper pipe. The rods range from 5/8 to 1/2 inch in diameter, and 32 inches to 8 feet or greater in length. The homeowner may purchase grounding kits consisting of earthing rods, a coupler and a wire clamp. The coupler joins the two earthing rods together. The wire clamp holds the wire to the top of the earthing rod. The manufacturer builds the rod to withstand corrosion while dissipating electrical energy.

Ground Installation

• Manufacturers recommend the homeowner place the grounding rod as deep as possible to lower electric resistance. Depending on the length of the earthing rod, the homeowner uses a ladder to pound the rod into the ground or digs a hole for the rod and fills it in. The homeowner attaches the coupler and clamp before inserting the rod into the ground. She leaves 4 to 5 inches of rod exposed to attach the wiring.

Ground Wire Attachment

• The ground wire for the rod may consist of 6-gauge copper, either a solid line or entwined strands. The homeowner attaches the wire as one short continuous line that's insulated, bare or covered. He places it on the rod and the metal structure, which are a short distance from each other, without the wire's pulling on the metal structure. Using a wire stripper, the homeowner takes off 1 inch of insulation from the insulated wire before attaching it to the rod with brass or copper clamps.