For any wiring installations, what is the maximum allowable conductor size specified for using solid copper wire?

The maximum allowable conductor size for using solid copper wire in typical wiring installations is related to factors such as the physical properties of the wire, ease of installation, and safety considerations. For solid copper conductors, sizes larger than 10 AWG become increasingly difficult to handle and install, particularly with regards to terminating the wires properly at terminals or connections.

Using a 10 AWG solid copper wire allows for sufficient current capacity for many common applications while still being manageable for installation. It provides a reliable balance between conductivity and ease of use. As the gauge size decreases, the wire diameter increases, which may pose handling challenges in confined spaces or during routing through electrical boxes. Therefore, while other sizes such as 8 AWG or larger can be used in specific circumstances, they are not generally recommended for typical residential wiring installations due to these handling difficulties.