❓ FAQ
+What wire size for 20 amps?
12 AWG copper for runs under 50ft at 120V. For longer runs, upgrade to 10 AWG to minimize voltage drop.
+What is the 80% rule?
NEC says continuous loads must not exceed 80% of breaker rating. A 20A breaker carries max 16A continuously.
+Do I need a permit?
Yes for new circuits, panel upgrades, or adding subpanels. Simple switch/outlet replacements typically do not need a permit.
+Can I use aluminum wire?
Yes for large feeders (4 AWG and up). Requires anti-oxidant compound on all connections. Must be 2 sizes larger than equivalent copper.