Three-Phase Power Calculator (Star/Delta)
Calculate Active (kW), Apparent (kVA), and Reactive (kVAR) power for three-phase systems. Features Star/Delta switching and regional voltage presets.
About
Industrial electrical systems rely on balanced three-phase power for transmission efficiency and motor torque. Field engineers often face errors when manually converting between Line-to-Line (VLL) and Line-to-Neutral (VLN) voltages, or when sizing circuit breakers for Star (Wye) versus Delta loads. Miscalculation leads to undersized conductors or nuisance tripping.
This tool automates the derivation of Active Power (P), Reactive Power (Q), and Apparent Power (S). It integrates the critical √3 factor for line calculations and applies the power factor (PF) to distinguish between resistive and inductive loads. Accuracy here ensures compliance with NEC and IEC load sizing standards.
Formulas
The relationship between power components in a balanced three-phase system involves the line voltage VLL, line current I, and power factor PF.
Apparent Power:
S = √3 × VLL × I
Active Power:
P = S × PF = √3 × VLL × I × cosφ
Reactive Power:
Q = √3 × VLL × I × sinφ
Reference Data
| Region / Standard | Voltage (VLL) | Frequency | Common Application |
|---|---|---|---|
| Europe (IEC) | 400 V | 50 Hz | Standard Industrial Mains |
| USA (NEC) | 480 V | 60 Hz | Industrial Motors & HVAC |
| USA (Lighting) | 208 V | 60 Hz | Commercial Small Power |
| Canada | 600 V | 60 Hz | Heavy Industry / Mining |
| UK (Legacy) | 415 V | 50 Hz | Older Installations |
| Japan (East) | 200 V | 50 Hz | Manufacturing |
| Australia | 400 V | 50 Hz | Standard Distribution |
| Brazil (Var) | 380 V | 60 Hz | Regional Grids |