According to master electrician James Hornof, for DC power, the red wire is generally positive and the black wire is usually negative. The red wire is a phase 2 hot wire, and the white wire. When you're dealing with electrical wiring, it's important to know which is positive and which is negative—but how are you supposed to tell them apart? The easiest way to tell is by looking at the color, but the colors mean different things depending on what kind of power is being used. Whether you are replacing a fixture, troubleshooting a circuit, or simply trying to understand your home's electrical. The positive wire carries the current from the power source to the load, while the negative wire returns the current back to the source. To identify the positive wire, look for markings such as a plus sign (+), the color red, or words like “positive” or “pos” on the wire insulation.
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