Which electrical equipment is required to have an equipment ground?

The requirement for an equipment ground is fundamentally based on safety guidelines that aim to protect both individuals and equipment from electrical faults. Metal enclosures of electrical equipment must be grounded to ensure that, in the event of a fault, an effective path is provided for the electrical current to return safely to the ground. This grounding helps prevent electrical shock hazards and minimizes the risk of fire due to stray currents.

Grounding all metal enclosures is critical because if there is an insulation failure or if the equipment becomes energized, the ground serves as a low-resistance path to safely carry the fault current away. This can facilitate the operation of protective devices, such as circuit breakers, which will trip and de-energize the faulty circuit.

In contrast, limiting the grounding requirement to only three-phase equipment, residential appliances, or lighting fixtures diminishes the overall safety standards set forth in electrical codes. All types of electrical equipment with metal enclosures require grounding to provide comprehensive safety measures, not just select categories.