“The secret of AWG,” he said, “is that the smaller the number, the bigger the wire, and the less resistance it has. Resistance makes heat. Heat starts fires. When you use 16 AWG where you need 10 AWG, you’re not being clever—you’re building a toaster inside your wall.”
His grandfather handed him a worn, greasy card. “Three rules,” he said. “One: length matters. A long 10 AWG wire acts like a short 14 AWG wire, so go thicker for long runs. Two: amperage is king. Find the device’s draw, look at the chart, and always pick the next size up. And three…” He tapped the 10 AWG cable. “When in doubt, go down a number. Heavier is safer.” awg wire sizes
“So how do I know which one?” Leo asked. “The secret of AWG,” he said, “is that