What is the minimum size equipment-bonding jumper required to connect a grounding-type receptacle to a grounded metal box?

The minimum size equipment-bonding jumper required to connect a grounding-type receptacle to a grounded metal box is 10 AWG copper. This requirement is based on electrical codes that ensure safety and reliability in grounding practices. The size of the equipment-bonding jumper is determined by factors such as the size of the circuit conductors and the overall installation requirements.

Using a 10 AWG copper jumper strikes a balance between providing sufficient conductivity and mechanical strength to ensure effective grounding while being appropriately sized to reduce the risk of overheating or failure. This size is compliant with safety standards and helps ensure that fault currents can effectively be carried back to the ground, enabling overcurrent devices to operate properly.

Larger sizes, such as 8 AWG, might provide extra capacity, but they exceed the minimum requirement. Conversely, smaller sizes such as 12 AWG or 14 AWG do not meet the standards set forth for safety and functionality in grounding systems, which is why they are not appropriate for this application.