1. What is a Three Phase Voltage Drop Calculator?

Definition: This calculator estimates the voltage drop in a three-phase electrical system based on current, cable length, and wire resistance.

Purpose: It helps electrical engineers and technicians ensure proper voltage levels in three-phase power distribution systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( V_{drop} \) — Voltage drop (volts)
• \( I \) — Current (amperes)
• \( L \) — Cable length (meters)
• \( R \) — Wire resistance (ohms per kilometer)
• \( \sqrt{3} \) — Three-phase system factor (≈1.732)

Explanation: The formula accounts for the three-phase system characteristics and converts resistance from Ω/km to Ω/m.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical equipment receives adequate voltage for optimal performance and prevents excessive power loss.

4. Using the Calculator

Tips: Enter the current in amps, cable length in meters, and wire resistance in Ω/km (default 0.5 Ω/km for typical copper wire). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is √3 used in the formula?
A: The √3 factor accounts for the phase difference in three-phase systems (120° between phases).

Q2: What's a typical wire resistance value?
A: For copper wire, typical values range from 0.5-1.0 Ω/km depending on wire gauge and temperature.

Q3: What's an acceptable voltage drop?
A: Generally, voltage drop should be less than 3% for branch circuits and 5% for feeders.

Q4: How does cable length affect voltage drop?
A: Voltage drop increases linearly with cable length - doubling the length doubles the voltage drop.

Q5: Does this account for power factor?
A: This simplified formula assumes unity power factor. For non-unity PF, a more complex formula is needed.