1. What is a Voltage Drop Calculator?

Definition: This calculator estimates the voltage drop in an electrical circuit based on current, wire length, and resistance.

Purpose: It helps electricians and engineers ensure proper voltage levels in electrical installations by predicting voltage loss over distance.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( VD \) — Voltage drop (volts)
• \( I \) — Current (amperes)
• \( L \) — Length of wire (feet)
• \( R \) — Resistance per 1000 feet (ohms)

Explanation: The factor of 2 accounts for the round-trip path of the circuit (both hot and neutral wires).

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop estimation ensures electrical devices receive adequate voltage, prevents overheating, and maintains system efficiency.

4. Using the Calculator

Tips: Enter the circuit current in amps, wire length in feet, and resistance per 1000 feet. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's an acceptable voltage drop?
A: Typically 3% for branch circuits and 5% for feeder circuits, but check local codes.

Q2: Where can I find resistance values?
A: Consult wire manufacturer specifications or NEC tables for standard values.

Q3: Why is length multiplied by 2?
A: It accounts for both the "hot" and "neutral" conductors in single-phase circuits.

Q4: Does this work for DC circuits?
A: Yes, the same formula applies to DC circuits.

Q5: How do I reduce voltage drop?
A: Use shorter runs, larger wire sizes, or reduce current load.