KVA to Amperage Calculator
Free convert kilovolt-amperes (kva) to current (amperes). calculate current from apparent power and voltage.
Input Parameters
Line-to-line for three-phase, line-to-neutral for single-phase
Results
Enter values to calculate
What is KVA to Amperage Conversion?
Converting kVA to amperage calculates the current (amperes) flowing in an electrical circuit based on the apparent power (kVA) and voltage. This is essential for sizing conductors, breakers, and electrical equipment.
The conversion depends on whether the system is single-phase or three-phase. Three-phase systems use the √3 factor due to the 120° phase relationship between phases.
This calculation is crucial in electrical engineering for determining current requirements, ensuring proper wire sizing, and selecting appropriate circuit protection devices.
KVA to Amperage Formulas
Single-Phase
Three-Phase
How to Convert KVA to Amperage
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1
Identify system type
Determine if it's single-phase or three-phase.
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2
Get kVA and voltage
Know the apparent power in kVA and the system voltage.
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3
Apply the formula
Single-phase: I = (kVA×1000)/V. Three-phase: I = (kVA×1000)/(√3×V).
Practical Examples
Example 1: Single-Phase
A 5 kVA single-phase load operates at 240 V. Calculate current.
Solution:
I = (kVA × 1000) / V = (5 × 1000) / 240
I = 20.83 A
Example 2: Three-Phase
A 50 kVA three-phase load operates at 480 V line-to-line. Calculate current.
Solution:
I = (kVA × 1000) / (√3 × V) = (50 × 1000) / (1.732 × 480)
I = 60.14 A
Applications
Wire Sizing
Determining conductor size based on current requirements to prevent overheating and voltage drop.
Circuit Protection
Selecting appropriate circuit breakers and fuses based on calculated current to protect equipment.
Load Analysis
Calculating total current draw for electrical panels and distribution systems.
Equipment Selection
Sizing transformers, generators, and electrical equipment based on current requirements.
Frequently Asked Questions
Why is current different for the same kVA in single vs three-phase?
Three-phase systems distribute power across three conductors. For the same kVA, three-phase current is lower per phase because power is shared: I_3ph = I_1ph / √3.
Does power factor affect this calculation?
No, kVA to amperage conversion doesn't depend on power factor. However, real power (kW) does: kW = kVA × PF, and current for real power would be different.
What voltage should I use?
For three-phase, use line-to-line voltage (phase-to-phase). For single-phase, use line-to-neutral voltage. This ensures correct current calculation.
Can I use this for DC systems?
For DC, kVA = kW (no reactive power), so I = (kW × 1000) / V. The formula is simpler since there's no phase relationship.
How do I account for efficiency losses?
This gives theoretical current. For actual current including losses, divide by efficiency: I_actual = I_theoretical / η. Efficiency is typically 0.85-0.95 for transformers.