1. What is a Voltage Line Drop Calculator?

Definition: This calculator estimates the voltage drop in an AC circuit based on current, resistance, and reactance.

Purpose: It helps electrical engineers and technicians determine voltage loss in power lines and circuits.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( VD \) — Voltage drop magnitude (volts)
• \( I \) — Current flowing through the circuit (amps)
• \( R \) — Resistance of the conductor (ohms)
• \( X \) — Reactance of the conductor (ohms)

Explanation: The current is multiplied by the impedance magnitude (square root of resistance squared plus reactance squared) to calculate voltage drop.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop estimation ensures adequate voltage at load points, prevents equipment malfunction, and maintains system efficiency.

4. Using the Calculator

Tips: Enter the current in amps, conductor resistance in ohms, and conductor reactance in ohms. Current must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between resistance and reactance?
A: Resistance opposes all current equally, while reactance opposes changes in current (frequency-dependent).

Q2: When can I ignore reactance in calculations?
A: For DC circuits or very short AC cables where reactance is negligible compared to resistance.

Q3: What's a typical acceptable voltage drop?
A: Generally 3-5% of supply voltage for branch circuits, 1-2% for feeders.

Q4: How does conductor size affect voltage drop?
A: Larger conductors have lower resistance, reducing voltage drop.

Q5: Does this calculator work for three-phase systems?
A: This calculates single-phase drop. For three-phase, multiply result by √3 (1.732).