1. What is Voltage Drop?

Voltage drop is the reduction in voltage in an electrical circuit between the source and load. It occurs due to the resistance in conductors and can affect equipment performance.

2. How Does the Calculator Work?

The calculator uses the voltage drop formula:

Where:

• \( I \) — Current in amperes (A)
• \( \text{Length} \) — Cable length in meters or feet
• \( \text{Resistance per Unit Length} \) — Conductor resistance in Ω/m or Ω/ft
• \( \times 2 \) — Factor for round trip (out and back)

Explanation: The formula calculates the voltage loss along a cable due to its resistance, doubling the result to account for the return path in DC or single-phase AC circuits.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical devices receive adequate voltage to operate correctly. Excessive voltage drop can cause equipment malfunction, overheating, and reduced efficiency.

4. Using the Calculator

Tips: Enter current in amperes, cable length in meters or feet, and resistance per unit length in Ω/m or Ω/ft. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why multiply by 2 in the formula?
A: The multiplication by 2 accounts for the round trip path of the current (out to the load and back to the source).

Q2: What's an acceptable voltage drop?
A: Generally, voltage drop should be less than 3% for branch circuits and 5% for feeder and branch circuits combined.

Q3: Does this formula work for both AC and DC?
A: This simplified version works for DC and single-phase AC. Three-phase AC requires a different calculation.

Q4: How do I find resistance per unit length?
A: Check cable specifications or use standard resistance values for common conductor materials (copper, aluminum).

Q5: When should I be concerned about voltage drop?
A: For long cable runs, high current applications, or sensitive electronic equipment where precise voltage is critical.