Guides: 3-phase
Three-phase power systems are the standard for industrial applications. These guides explain how 3-phase power works, how to calculate it, and when to use it in your electrical designs.
About This Topic
Three-phase power systems are the standard for industrial applications. These guides explain how 3-phase power works, how to calculate it, and when to use it in your electrical designs.
Recommended Learning Path
- Learn the fundamentals of 3-phase power systems
- Understand voltage relationships and phase angles
- Calculate current, power, and kVA for 3-phase loads
- Apply 3-phase calculations to motor and equipment sizing
- Explore power factor and efficiency considerations
Related Calculators
Use these professional calculators to apply the concepts covered in the 3-phase guides:
3-Phase Power Calculator
Calculate three-phase current, kW, and kVA for industrial electrical systems.
Use ToolFactory Load Calculator
Determine total electrical load, current, and breaker ratings for industrial facilities.
Use ToolTransformer Size Calculator
Calculate recommended transformer kVA rating based on load and power factor.
Use ToolAll Articles
Browse all 8 guides covering 3-phase topics:
3 Phase Power: What It Is, How It Works & Why Industry Uses It
What is 3 phase power? Three AC waveforms 120° apart for industrial motors and plants—vs single-phase, wye vs delta, and when you need it.
Read Full Article3 Phase Power Formula & Calculation Examples
3 phase power formula P = √3×V×I×PF and current I = kVA×1000/(√3×V). Worked examples at 400V & 480V—free calculator to verify kW, kVA, and amps.
Read Full ArticleHow to Measure Power Factor in 3-Phase Systems: Complete Guide
Measure power factor accurately in 3-phase systems. Step-by-step instructions using power analyzers, clamp meters, and voltmeters with troubleshooting tips.
Read Full Article3-Phase Unbalance % Formula (Neutral Current & Correction)
Calculate phase unbalance percentage and neutral current in 3-phase systems—formulas, IEEE limits, correction steps. Free worked example.
Read Full ArticleOLTC vs OCTC Tap Changer (Selection & Cost Comparison)
Choose on-load vs off-load tap changers: outage rules, OLTC cost tradeoffs, 13.8 kV example. Free decision table for 3-phase engineers.
Read Full ArticleTransformer Voltage Regulation Formula (%Z & Secondary VD)
Calculate transformer voltage regulation with %Z and load PF—480 V worked example. Distinguish regulation from conductor voltage drop.
Read Full ArticleThree Phase Transformer Sizing (kVA Calculation and Examples)
Three phase transformer sizing for electrical engineers and designers: kVA formula, line vs phase voltage, balanced and unbalanced loads, with 400V/480V examples.
Read Full ArticleCommon Transformer Tap Changer Faults
Learn to identify, diagnose, and prevent common tap changer faults in 3-phase transformers. Symptoms, causes, and maintenance for OLTC and OCTC.
Read Full Article