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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.

Diagrams and colors

Wiring diagramsSingle-pole, 3-way, 4-way, switched receptacles, fans, smart switches, GFCI line and load, photocells and motor start-stop.Wire color codesPhase colors for 120/240, 120/208, 277/480 and high-leg delta, with a panel circuit-number lookup.

Math and tables

Formulas and conversionsOhm's law, single- and three-phase power, power factor, horsepower, and unit conversions, with worked examples.TransformersFull-load current, primary and secondary protection under 450.3(B), and common connections.Grounding and bondingEGC sizing (250.122) and GEC sizing (250.66), with bonding basics.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.

Code and the field

Code lookup by topicFind the article and section for GFCI, spacing, supports, working space, grounding, motors, EV chargers and more.Field guideBending, pulling wire, terminations and torque, safety and PPE, and an apprentice corner.