NEC Articles & Explainers

Long-form, plain-English breakdowns of the code sections that show up most often on the journeyman exam — and most often in real construction submittals.

• Reading Table 310.16 — Conductor Ampacity, Step by Step
  The 60/75/90 °C columns, termination temperature limits, ambient and conductor-count adjustments, and the small-conductor rule that overrides the table. With worked examples for 12 AWG, 4 AWG, and 500 kcmil.
• Voltage Drop — Formulas, NEC Rules, and Worked Examples
  Single-phase and three-phase formulas, the K constant for copper and aluminum, the 3% / 5% NEC recommendation, and how to back-solve for the wire size you actually need.
• Sizing the Grounding Electrode Conductor — Table 250.66 Explained
  How GEC size relates to service-conductor size, the three "max-out" exceptions for rod, concrete-encased, and ring electrodes, and what counts as the "largest" service conductor for parallel sets.