Educational resources about voltage drop, wire sizing, NEC guidelines, and electrical calculations.
The complete guide to voltage drop calculations. Learn the formulas for DC, single-phase AC, and three-phase circuits with worked examples, common mistakes, and practical applications.
Read the full guide →Understand the NEC 210.19(A) and 215.2(A) informational notes that recommend 3% max drop for branch circuits and 5% for branch + feeder combined. Includes code references and inspector expectations.
Read article →Master every voltage drop formula: VD = 2 x I x R x L for DC, VD = 2 x I x Z x L for single-phase AC, and the three-phase variant with the 1.732 factor. Includes 7+ worked examples and common pitfalls.
Read article →Complete AWG wire sizing reference from 14 AWG to 750 kcmil. Includes ampacity ratings at 60/75/90 degrees C, resistance values for copper and aluminum, and quick-lookup voltage drop tables.
Read article →Why 12V DC systems are especially sensitive to voltage drop and how to size wires for RVs, boats, and off-grid solar. Covers ABYC standards, fuse sizing, and real-world wiring examples.
Read article →Step-by-step three-phase voltage drop calculations for 208V, 480V, and 600V industrial systems. Covers delta vs wye configurations, power factor correction, and motor feeder sizing.
Read article →Side-by-side comparison of copper and aluminum conductors for resistivity, ampacity, weight, cost, and voltage drop performance. Includes guidance on when aluminum feeders make economic sense.
Read article →Five proven strategies to reduce voltage drop: upsizing conductors, shortening runs, raising system voltage, paralleling conductors, and improving power factor. Cost-benefit analysis for each method.
Read article →Design flicker-free LED landscape lighting systems. Covers 12V and 24V transformer selection, hub-and-spoke vs daisy-chain wiring, and how to keep voltage drop under 1V across the entire run.
Read article →Minimize energy losses in solar PV installations from panel to inverter and inverter to panel. Covers string sizing, DC home runs, AC output wiring, and NEC 690 requirements for PV systems.
Read article →Head-to-head comparison of our calculator vs Southwire's tool. Covers feature differences, supported circuit types, wire materials, mobile usability, and calculation accuracy across 5 test scenarios.
Read article →Put the knowledge from these guides into practice with our free voltage drop calculator. Supports DC, single-phase AC, and three-phase systems with NEC-compliant formulas.