1. What is a DC Voltage Drop Calculator?

Definition: This calculator determines the voltage drop in a DC electrical circuit according to UK standards.

Purpose: It helps electricians and engineers ensure proper voltage levels in DC power systems by calculating the potential drop across cables.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( VD \) — Voltage drop (volts)
• \( \rho \) — Resistivity of conductor material (ohm-m)
• \( L \) — Length of cable (meters)
• \( I \) — Current flowing through cable (amps)
• \( A \) — Cross-sectional area of conductor (m²)

Explanation: The factor of 2 accounts for the return path in DC circuits. The formula calculates the voltage lost due to the resistance of the conductors.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical devices receive adequate voltage and helps prevent performance issues or equipment damage.

4. Using the Calculator

Tips: Enter the conductor resistivity (default 1.68×10⁻⁸ ohm-m for copper), cable length in meters, current in amps, and conductor area in m². All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is voltage drop important in DC systems?
A: Excessive voltage drop can lead to insufficient voltage at the load, causing equipment to malfunction or operate inefficiently.

Q2: What's the typical resistivity value for copper?
A: Copper has a resistivity of about 1.68×10⁻⁸ ohm-m at 20°C. For aluminum, use 2.65×10⁻⁸ ohm-m.

Q3: How do I convert conductor area from mm² to m²?
A: Divide mm² value by 1,000,000 (e.g., 2.5 mm² = 2.5×10⁻⁶ m²).

Q4: What's an acceptable voltage drop percentage?
A: UK standards typically recommend ≤ 3% for lighting circuits and ≤ 5% for other circuits.

Q5: Does temperature affect the calculation?
A: Yes, resistivity changes with temperature. For precise calculations, adjust resistivity for the operating temperature.