Analyze DC and AC load current with precision. Compare system demand carefully before selecting protection. Choose breakers wisely for safer circuits and dependable performance.
Enter load details to estimate line current, breaker sizing, circuit loading, and energy use. Results appear above this form after submission.
| Case | System | Voltage | Input Power | PF | Efficiency | Estimated Current |
|---|---|---|---|---|---|---|
| Pump Motor | Three Phase | 415 V | 15 kW | 0.88 | 94% | 25.27 A |
| Compressor | Single Phase | 230 V | 4.2 kW | 0.92 | 96% | 20.65 A |
| DC Heater | DC | 48 V | 1.8 kW | 1.00 | 98% | 38.27 A |
DC real power: I = P ÷ (V × η)
Single phase real power: I = P ÷ (V × PF × η)
Three phase real power: I = P ÷ (√3 × V × PF × η)
Single phase apparent power: I = S ÷ V
Three phase apparent power: I = S ÷ (√3 × V)
Resistance mode: I = V ÷ R
Use current with a design safety factor to estimate a practical breaker rating. Compare calculated current with circuit rating to judge loading margin.
Current load is the electrical current a device or circuit draws during operation. It depends on voltage, power demand, power factor, and efficiency.
Power factor changes the relationship between real power and current. Lower power factor means the same useful power needs more current from the supply.
In balanced three-phase systems, line quantities are related through vector geometry. The √3 term comes from the phase difference between the three sinusoidal waveforms.
Yes. If equipment is not perfectly efficient, it draws more input power than its useful output. That raises the supply current.
It is a rounded protective device size based on calculated current and the selected safety factor. Final sizing should still follow local electrical codes.
Use apparent power mode when the equipment rating is given in VA or kVA. This is common for transformers, UPS systems, and some power electronics.
It compares the estimated current with the circuit ampere rating. A higher percentage means less spare capacity for safe continuous operation.
No. It is a strong engineering estimate, but final conductor sizing, derating, protection, and installation checks should follow applicable standards and site conditions.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.