Wireman · Reference · 2023 NEC ·
Reference
Reference
The numbers and diagrams you look up on the job, written and drawn by us and checked against the code.
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Wire color codesPhase colors for 120/240, 120/208, 277/480 and high-leg delta, with a panel circuit-number lookup.Wire ampacityTable 310.16 values with derating, inside the wire size calculator.Conduit and conductor areasChapter 9 Tables 4 and 5, inside the conduit fill calculator.Motor full-load currentTables 430.248 and 430.250, inside the motor calculator.
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FormulasOhm's law, power, three-phase, power factor and efficiency, with worked examples.
ConversionsWatts, amps, kVA and horsepower; fractions and decimals; metric.
Wiring diagramsThree-way and four-way switching, motor control, start-stop, and transformer connections.
TransformersFull-load current, connections, and primary and secondary protection.
Grounding and bondingEquipment grounding conductor and grounding electrode conductor sizing.
Code lookup by topicFind the article and section for common situations, with plain-language notes.