Wire Voltage Loss Calculator

Voltage Loss Formula:

\[ \% Loss = \frac{2 \times L \times I \times R}{V} \times 100 \]

Length (L):

Current (I):

Resistance (R):

Ω/1000 ft

Voltage (V):

Voltage Loss Percentage:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Wire Voltage Loss?

Wire voltage loss refers to the reduction in voltage that occurs when electrical current flows through a conductor due to the conductor's resistance. This phenomenon is also known as voltage drop and is an important consideration in electrical system design.

2. How Does the Calculator Work?

The calculator uses the voltage loss formula:

\[ \% Loss = \frac{2 \times L \times I \times R}{V} \times 100 \]

Where:

\( L \) — Length of conductor (feet)
\( I \) — Current flowing through conductor (Amperes)
\( R \) — Resistance per 1000 feet (Ohms/1000 ft)
\( V \) — Source voltage (Volts)
\( 2 \) — Factor for round trip (out and back) circuit

Explanation: The formula calculates the percentage of voltage lost due to conductor resistance over the specified length at the given current.

3. Importance of Voltage Loss Calculation

Details: Calculating voltage loss is crucial for ensuring proper operation of electrical equipment, preventing overheating, maintaining efficiency, and complying with electrical codes that typically limit voltage drop to 3-5% for branch circuits.

4. Using the Calculator

Tips: Enter conductor length in feet, current in amperes, resistance per 1000 feet in ohms, and source voltage in volts. All values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is an acceptable voltage loss percentage?
A: For branch circuits, the National Electrical Code recommends maximum voltage drop of 3% for feeders and 5% for branch circuits combined.

Q2: How does wire size affect voltage loss?
A: Larger wire sizes have lower resistance per foot, resulting in less voltage loss for the same current and distance.

Q3: Why is there a factor of 2 in the formula?
A: The factor of 2 accounts for the round-trip path of current - from source to load and back to source.

Q4: When is voltage loss calculation most important?
A: Critical for long wire runs, high current applications, and sensitive electronic equipment that requires stable voltage.

Q5: How can I reduce voltage loss?
A: Use larger wire gauge, shorten conductor length, reduce current load, or increase source voltage where possible.