Amps Per Phase Calculator

Three-Phase Current Formula:

\[ I_{phase} = \frac{P}{\sqrt{3} \times V_{line} \times PF} \]

Current Per Phase (I_phase):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Amps Per Phase?

Amps Per Phase refers to the current flowing through each phase in a three-phase electrical system. It's a crucial parameter for designing electrical systems, selecting appropriate circuit breakers, and ensuring safe operation of electrical equipment.

2. How Does the Calculator Work?

The calculator uses the three-phase current formula:

\[ I_{phase} = \frac{P}{\sqrt{3} \times V_{line} \times PF} \]

Where:

\( I_{phase} \) — Current per phase (Amperes)
\( P \) — Total power (Watts)
\( V_{line} \) — Line-to-line voltage (Volts)
\( PF \) — Power factor (0 to 1)
\( \sqrt{3} \) — Approximately 1.732

Explanation: This formula calculates the current flowing through each individual phase in a balanced three-phase system, accounting for the total power, line voltage, and power factor.

3. Importance of Current Calculation

Details: Accurate current calculation is essential for proper sizing of conductors, circuit breakers, transformers, and other electrical components. It ensures system safety, efficiency, and compliance with electrical codes.

4. Using the Calculator

Tips: Enter total power in watts, line-to-line voltage in volts, and power factor (between 0 and 1). All values must be positive numbers with power factor not exceeding 1.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between line current and phase current?
A: In three-phase systems, line current is the current in the supply lines, while phase current is the current through each winding. In star connection, they are equal; in delta connection, phase current = line current / √3.

Q2: Why is power factor important in current calculation?
A: Power factor represents the ratio of real power to apparent power. Lower power factors result in higher current for the same real power, requiring larger conductors and equipment.

Q3: What is a typical power factor value?
A: Power factor typically ranges from 0.8 to 0.95 for industrial loads. Resistive loads have PF=1, while inductive loads (motors, transformers) have PF less than 1.

Q4: Can this calculator be used for single-phase systems?
A: No, this calculator is specifically for three-phase systems. For single-phase, use I = P / (V × PF).

Q5: What safety margin should I add to calculated current?
A: Typically, add 25% safety margin for circuit breaker sizing and 15-20% for conductor sizing to account for load variations and future expansions.