Voltage Drop Calculator For Parallel Feeders Wire

Voltage Drop Equation for Parallel Feeders:

\[ VD = \frac{I}{n \times L \times R_{wire}} \div V \times 100 \]

Current (I):

amperes

Number of Feeders (n):

number

Length (L):

feet

Wire Resistance (R_wire):

ohms/ft

Voltage (V):

volts

Voltage Drop (VD):

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1. What is Voltage Drop in Parallel Feeders?

Voltage drop in parallel feeders refers to the reduction in voltage that occurs when current flows through multiple parallel conductors. It's important to calculate this to ensure proper operation of electrical equipment and compliance with electrical codes.

2. How Does the Calculator Work?

The calculator uses the voltage drop equation for parallel feeders:

\[ VD = \frac{I}{n \times L \times R_{wire}} \div V \times 100 \]

Where:

\( VD \) — Voltage drop (%)
\( I \) — Current (amperes)
\( n \) — Number of parallel feeders
\( L \) — Length of conductors (feet)
\( R_{wire} \) — Resistance of wire (ohms/ft)
\( V \) — Voltage (volts)

Explanation: The equation calculates the percentage voltage drop based on the current divided by the total parallel conductance, then divided by the system voltage.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical equipment receives adequate voltage, prevents excessive power loss, and maintains system efficiency in parallel feeder configurations.

4. Using the Calculator

Tips: Enter current in amperes, number of parallel feeders, length in feet, wire resistance in ohms per foot, and system voltage in volts. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is an acceptable voltage drop percentage?
A: Typically 3% for branch circuits and 5% for feeder circuits, but consult local electrical codes for specific requirements.

Q2: Why does parallel feeders reduce voltage drop?
A: Multiple parallel conductors effectively reduce the total resistance, thereby reducing the voltage drop for a given current.

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

Q4: Should I use actual or nominal voltage in calculations?
A: Use nominal system voltage (e.g., 120V, 240V) unless you know the exact operating voltage at the source.

Q5: Does temperature affect voltage drop calculations?
A: Yes, wire resistance changes with temperature. For precise calculations, use resistance values at operating temperature.