Cable Size [verified] -

If your cable is too small for the load, that heat doesn’t just dissipate—it builds up, melts the insulation, and starts a fire. In fact, undersized wiring is one of the leading causes of electrical house fires.

Note: Aluminum wire (common for service entrances) needs to be 1-2 sizes LARGER than copper to carry the same load. We see it all the time: A homeowner buys a massive 10,000-watt space heater and plugs it into an extension cord that looks like a lamp cord. The heater tries to draw 40 amps. The 18-gauge cord is rated for 7 amps. cable size

Your extension cord must be as thick as the wall wire feeding the outlet. If your tool draws 15 amps, you need a 14 AWG cord (or thicker). How to Calculate the Right Size If you’re installing a new circuit, use the 80% rule (Continuous Load Rule). If a device runs for more than 3 hours (lights, EV charger, heaters), you can only load the breaker to 80% of its rating. If your cable is too small for the