What is the typical wire size used for general-purpose branch circuits in residential installations?

The typical wire size used for general-purpose branch circuits in residential installations is 12 AWG. This gauge is commonly chosen to handle common household circuits, such as lighting and receptacles, which usually operate on a 20-amp circuit.

Using 12 AWG wire helps ensure safe operation and minimizes the risk of overheating, as it can carry the necessary current load without exceeding its rated capacity. It also provides a balance between sufficient conductivity and flexibility for installation in various settings.

The other wire sizes are less suitable for general-purpose branch circuits; for example, 14 AWG is often used for 15-amp circuits and might not provide adequate capacity for heavier loads. Meanwhile, 10 AWG is typically reserved for larger appliances that require more current, such as dryers or water heaters, and 16 AWG is too small for typical residential applications, as it cannot handle the required current safely.