Cable Power Drop Calculator

Voltage Drop Formula:

\[ Voltage Drop = I \times R \times Length \times 2 \]

Voltage Drop (V):

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1. What is AC Cable Voltage Loss?

AC cable voltage loss refers to the reduction in voltage that occurs when electrical current flows through a cable due to the cable's resistance. This voltage drop can affect the performance of electrical equipment and must be calculated to ensure proper system design.

2. How Does the Calculator Work?

The calculator uses the voltage drop formula:

\[ Voltage Drop = I \times R \times Length \times 2 \]

Where:

\( I \) — Current flowing through the cable (amps)
\( R \) — Resistance per unit length of the cable (ohms/km)
\( Length \) — Length of the cable run (km)
\( 2 \) — Factor accounting for both supply and return paths

Explanation: The formula calculates the total voltage drop by multiplying current, resistance, cable length, and the factor of 2 for the complete circuit path.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation is essential for designing efficient electrical systems, ensuring equipment receives adequate voltage, preventing power loss, and maintaining system safety and reliability.

4. Using the Calculator

Tips: Enter current in amps, resistance in ohms per kilometer, and cable length in kilometers. All values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why multiply by 2 in the formula?
A: The factor of 2 accounts for both the supply (live) and return (neutral) conductors in a single-phase AC circuit.

Q2: What is an acceptable voltage drop percentage?
A: Generally, voltage drop should not exceed 3% for branch circuits and 5% for feeder circuits, but local electrical codes may specify different requirements.

Q3: How does cable size affect voltage drop?
A: Larger cable sizes have lower resistance, resulting in less voltage drop for the same current and distance.

Q4: Does this formula work for DC circuits?
A: Yes, the same formula applies to DC circuits, though AC circuits may have additional factors like power factor and reactance.

Q5: When should I be concerned about voltage drop?
A: Be concerned when voltage drop exceeds recommended limits, causes equipment malfunction, or results in significant power loss over long cable runs.