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Electrical Engineering Guides

Learn the concepts behind the calculators, understand the units, and recognize where simplified formulas stop being enough.

Power and Systems

kW vs. kVA

Understand real power, apparent power, reactive power, and power factor.

Single-Phase vs. Three-Phase

Compare voltage relationships, power formulas, and typical uses.

Motor Current and Power Factor

Learn why horsepower alone does not determine motor current.

Power Factor Explained

Understand current, kVA, distortion, and correction.

Generator kW vs. kVA

Review running load, reserve, and transient limits.

Transformer Sizing

Understand kVA, ratio, loading, and installation factors.

Fault MVA and Per Unit

Connect system bases, transformer impedance, and short-circuit current.

Circuits and Energy

Ohm's Law Explained

Connect voltage, current, resistance, and power.

Voltage Drop Guide

Understand conductor resistance, circuit length, and percentage drop.

Battery Ah vs. Wh

Compare charge capacity with stored-energy capacity.

Amps from Watts

Use the correct formula for DC and AC systems.

Series vs. Parallel

Compare resistance, voltage, current, and power.

LED Resistor Selection

Choose resistance and power rating.

Solar Peak Sun Hours

Use irradiance data in PV estimates.

AC vs. DC Voltage Drop

Compare resistance and impedance methods.

How to Use These Guides

Each guide explains terminology, derives the basic relationships, works through an example, identifies common mistakes, and links directly to relevant calculators.

Guides explain general engineering relationships. They do not replace equipment data, applicable standards, electrical codes, or professional design review.