Hvac School - For Techs, By Techs

In this short podcast, Bryan covers a common electrical myth about wire length and its relationship with the National Electrical Code. The NEC is concerned with safety—protecting buildings and people—but less so with making sure things work. Wire sizing is a common topic, and length is important because it can contribute to the voltage drop in a circuit. In many cases, we refer to the MCA (minimum circuit ampacity) to select an appropriate wire size.  If you run more current through an undersized conductor, it gets hotter and will experience a voltage drop—though not proportionally. It’s worth noting that nothing in the circuit is fixed; voltage, amperage, and resistance all follow Ohm’s law but are variable as different things start happening in a circuit. In many cases, the NEC generally doesn’t require us to size conductors to accommodate for voltage drop. Conductors have some degree of resistance, so longer wires will result in a greater voltage drop than you would see in a shorter wire. It makes sense fo