Learning Library
Electrical guides
Structured tutorials and reference guides for electrical calculations, NEC interpretation, and practical design workflows.
- Published guides
- 57
- Categories
- 12
- Focus
- NEC-oriented study
Featured Guides
Start with the most-used tutorials for calculations, design review, and code-aware electrical work.
Ohm's Law Fundamentals for Voltage, Current, Resistance, and Power in U.S. Electrical Work
Use V = I x R and power formulas to solve simple DC and resistive AC checks, review voltage drop, and know when impedance replaces resistance in U.S. electrical troubleshooting.
Power Factor Formula Guide | kW, kVA, kVAR
Use PF = kW/kVA to understand power factor, leading and lagging loads, kVAR correction, utility penalties, and calculator handoffs.
Ohms Law Formula Guide | V, I, R and Power
Use Ohms Law formulas: 12 V across 4Ω gives 3 A and 36 W; solve V=IR, I=V/R, R=V/I, P=VI, and power wheel examples.
Electrical Power Formulas Guide | Calculator Workflow
Use this power formulas guide to choose DC, single-phase, three-phase, PF, kW, kVA, HP, current, voltage, and calculator inputs.
3-Phase Formula Guide | kW, Amps & kVA
Use three-phase formulas for kW, amps, kVA, line voltage, current, power factor, and wye/delta inputs before calculator checks.
Voltage Drop Guide | Formula and Calculator Workflow
Use this voltage drop guide to choose phase, voltage, current, distance, conductor material, wire size, and NEC design-target inputs.
Kirchhoff Laws Guide | KCL and KVL Workflow
Use this Kirchhoff laws guide to choose KCL, KVL, nodal, mesh, supernode, supermesh, and circuit calculator inputs.
NEC Overview Guide | NFPA 70 Articles & Workflow
Use this NEC overview to confirm adopted NFPA 70, then route Article 220 loads, 240 protection, 250 grounding, and 310 conductors to calculators.
NEC Ampacity Chart | Table 310.16 Wire Sizes
Use NEC 310.16 ampacity chart for copper/aluminum wire sizes, 60C/75C/90C columns, terminal limits, and 30A/50A handoffs.
Breaker Size Chart | NEC 240.6 & Wire Gauge
Check NEC 240.6 breaker sizes and common copper limits: 14 AWG -> 15A, 12 AWG -> 20A, 10 AWG -> 30A; use calculator for 125% loads.
Lighting Calculation Guide | Lumen Method Workflow
Use this lumen method guide to set target illuminance, room area, fixture lumens, CU, LLF, layout, LPD, and calculator verification.
Motor Starting Current Guide | Inrush Method Workflow
Use this motor starting current guide to choose FLA, HP, voltage, NEMA code, starter method, current limit, and voltage-drop inputs.
Motor Power Formulas Guide | HP, kW, Torque and Current
Use this motor power formulas guide to choose HP, kW, torque, speed, efficiency, power factor, voltage, and calculator inputs.
Power System Fundamentals: Voltage Levels, One-Line Diagrams, and Study Workflow
Map U.S. generation, transmission, substations, feeders, transformers, and utilization voltages into load-flow, short-circuit, voltage-drop, and protection checks.
Solar PV System Sizing & Inverter Guide
Size solar PV arrays from monthly kWh, panel count, inverter limits, battery backup needs, and payback assumptions.
Arc Flash Calculator Workflow | IEEE 1584
Use an arc flash calculator workflow: start with fault current and clearing time, then review IEEE 1584 incident energy, boundary and NFPA 70E arc rating.
Insulation Resistance Test | Megger, PI & DAR
Use guide for insulation resistance tests: select megger voltage, enter PI/DAR readings, correct to 40C, and document trends.
Wire Sizing Guide for NEC Ampacity, Voltage Drop, and Terminal Temperature Limits
Use ampacity, continuous-load rules, terminal temperature limits, voltage drop, and motor or feeder checks to choose conductor size for U.S. branch circuits and feeders.
Voltage Drop Formulas | Single-Phase, 3-Phase & NEC Notes
Single-phase and three-phase voltage-drop checks with NEC informational-note targets, conductor resistance, ampacity, terminals, and project specifications.
Lighting Formulas | Lumens, Lux & Foot-Candles
Use lighting formulas for lumen method: 500 lux over 20 m x 15 m with 4,000 lm lamps, CU 0.7 and LLF 0.8 needs 67 fixtures.
Transformer kVA Chart | Sizing Table and Current
Use transformer kVA sizing tables with single-phase/three-phase formulas, voltage, current, margin, impedance, NEC 450.3, and fault review.
Browse by Category
Explore the guide family that matches your current task, study topic, or field workflow.
Basic Electrical
U.S. voltage, power, impedance, and grounding fundamentals
Circuit Analysis
U.S. series-parallel, phasor, impedance, and troubleshooting workflow
Code Compliance
U.S. NEC adoption, ampacity, breaker sizing, dwelling load screening, and inspection-facing code review
Lighting Design
U.S. lighting calculations, luminaire selection, emergency egress, and control strategy workflow
Motor Control
Motor control systems and applications
Power Systems
U.S. distribution planning, transformer selection, and power-quality workflow
Renewable Energy
U.S. solar, battery storage, wind, and hybrid power workflow
Safety & Protection
Arc-flash risk review, short-circuit screening, coordination, and grounding/bonding workflow for U.S. electrical systems
Testing & Measurement
Field verification, commissioning, and measurement workflow for U.S. electrical systems
Wire & Cable
U.S. conductor sizing, raceway fill, and voltage-drop workflow
Lighting
Lighting formulas, photometric reference, and quick illuminance checks for U.S. projects
Transformers
U.S. transformer sizing, voltage selection, and protection workflow
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