SOLID VS STRANDED WIRE
There are two different types of aluminum wiring that are found in homes: solid and stranded. Solid wires are one piece of wire, and are typically found on the lower amperage (15A & 20A) 120V circuits in the home. Stranded wires are multiple pieces of wire bundled together to form a larger wire, and are typically found on the higher amperage (>25A) 240V circuits in the home. Solid wire is not commonly used in residential construction nowadays, but stranded aluminum wire is quite common, and properly installed is considered safe for residential use.