It is critical that there be good bonding of several copper-bonded earthing rods to ensure that a solid and safe grounding system is formed. The National Electrical Code (NEC) dictates that all the ground rods need to be bonded together in order to create an integrated Grounding Electrode System (GES). The bonding makes all the components of the electrical system have a common ground potential, lowering the possibility of voltage differences that cause electrical shock or equipment destruction. Failing to connect ground rods together can lead to electrical code non-compliance and greater safety risks.
When installing more than one ground rod, it's essential to space them to get the best out of them. A general rule is to space rods at least twice their length apart; for instance, 8-foot rods should be spaced 16 feet apart. This spacing provides an opportunity for every rod to properly dissipate electrical energy into the ground without interference from neighboring rods. The rods must be joined by a continuous conductor, usually a bare copper wire of not less than #6 AWG, to provide a low-impedance path between them. Connections must be made with proper clamps or by exothermic welding to ensure long-term reliability.
In applications where ground rods are placed at various points across a property, for example, at the primary electrical service entrance and at a separate building, it's important to bond these ground rods together. This can be done by routing a bonding conductor around a building perimeter or along an accessible route, connecting all the ground rods. Effective bonding not only provides safety but also leads to electrical code compliance, with a grounding system that is effective in safeguarding equipment and human lives against electrical failure and lightning strikes.