Voltage Drop Calculator (Simple)

Simplified Voltage Drop Formula:

\[ V_d = \frac{2 \times I \times L \times R}{1000} \]

Voltage Drop (V_d):

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1. What is the Simplified Voltage Drop Calculation?

The simplified voltage drop calculation estimates the voltage loss in an electrical circuit due to conductor resistance. It provides a quick assessment of voltage drop for DC or single-phase AC systems with resistive loads.

2. How Does the Calculator Work?

The calculator uses the simplified voltage drop formula:

\[ V_d = \frac{2 \times I \times L \times R}{1000} \]

Where:

\( V_d \) — Voltage drop (V)
\( I \) — Current (A)
\( L \) — Length of conductor (m)
\( R \) — Resistance per unit length (Ω/km)

Explanation: The factor of 2 accounts for the round-trip path (out and back) in a single-phase system. The division by 1000 converts resistance from Ω/km to Ω/m.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation is essential for ensuring electrical equipment operates within specified voltage limits, preventing performance issues, equipment damage, and safety hazards.

4. Using the Calculator

Tips: Enter current in amperes (A), length in meters (m), and resistance in ohms per kilometer (Ω/km). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: When is this simplified formula appropriate?
A: This formula is suitable for DC circuits and single-phase AC circuits with primarily resistive loads at power frequencies.

Q2: What are acceptable voltage drop limits?
A: Generally, voltage drop should not exceed 3% for branch circuits and 5% for feeder and branch circuits combined, but specific codes and applications may vary.

Q3: How do I find the resistance value (R)?
A: Resistance values are typically available from conductor manufacturer specifications or electrical code tables based on conductor material and size.

Q4: Does this formula account for power factor?
A: No, this simplified formula does not account for power factor. For reactive loads, a more complex calculation considering impedance is needed.

Q5: Why multiply by 2 in the formula?
A: The factor of 2 accounts for the round-trip path length in single-phase systems (both the outgoing and return conductors).