How many separate grounding means are typically required in most jurisdictions?

In many jurisdictions, local codes and the National Electrical Code (NEC) often stipulate that a minimum of two separate grounding means are required for safety and reliability in electrical systems. This designation usually includes a grounding electrode system that connects the building's electrical system to the earth, providing a safe path for fault current and preventing electrical shock hazards.

Having at least two grounding means serves several purposes: it ensures redundancy in grounding paths, which is critical in the event of a failure in one grounding system, and it helps to mitigate the potential for ground loops, which can lead to interference and other electrical issues. Most residential and commercial installations will have a combination of grounding electrodes, such as ground rods, metal water pipes, or concrete-encased electrodes, which fulfill this requirement.

The necessity for multiple grounding methods reflects a broader principle of enhancing safety in electrical installations, as well as compliance with regulatory safety standards that govern electrical work in various regions.