📐 Reference Library
Tables, formulas, diagrams, and field workflows — the stuff you look up on the tailgate.
16 guides · page 2 of 2
Three-Phase Power Basics for Apprentices
The first time you meet three-phase, it feels like a different language. It isn't — it's just three single-phase waves working together, and once that clicks, wye, delta, and those odd voltages all start to make sense. Here's the plain-English foundation.
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Box Fill Explained: How to Count It Right (NEC 314.16)
Overstuffed boxes cause damaged insulation, overheating, and failed inspections. Box fill is simple once you know what counts as what — here's the working electrician's breakdown of counting conductors, devices, clamps, and grounds.
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Conduit Fill Explained: The 40% Rule and Why It Matters
Conduit fill isn't bureaucratic box-checking — it's about heat and pullability. Here's the working electrician's explanation of the fill percentages, where the numbers come from, and how to get it right without guessing.
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Wire Color Codes: What the Colors Mean (and When They Lie)
Black is hot, white is neutral, green is ground — until a switch loop, a 240V circuit, or a previous owner's creativity says otherwise. The color conventions, the legal re-markings, and the rule that colors are clues, not proof.
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