1. What Is Voltage Drop?

Voltage drop refers to the reduction in voltage in an electrical circuit between the source and load. It occurs due to the resistance of conductors and can affect equipment performance and efficiency.

2. How Does The Calculator Work?

The calculator uses the voltage drop formula for single-phase circuits:

Where:

• \( VD \) — Voltage drop (Volts)
• \( I \) — Current (Amperes)
• \( R \) — Resistance per 1000 feet (Ω/kft)
• \( L \) — Length of conductor (feet)

Explanation: The factor of 2 accounts for the round trip path in single-phase circuits (both hot and neutral conductors).

3. Importance Of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical equipment operates within specified voltage ranges, prevents performance issues, reduces energy losses, and complies with electrical codes.

4. Using The Calculator

Tips: Enter current in amperes, resistance in ohms per thousand feet, and length in feet. All values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

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

Q2: Why is voltage drop important?
A: Excessive voltage drop can cause motors to overheat, lights to dim, and electronic equipment to malfunction or fail.

Q3: How can I reduce voltage drop?
A: Use larger conductor sizes, reduce circuit length, or decrease the load current to minimize voltage drop.

Q4: Does this formula work for three-phase systems?
A: No, this is for single-phase systems. Three-phase systems use different formulas accounting for phase relationships.

Q5: Where can I find conductor resistance values?
A: Conductor resistance values are available in NEC tables or manufacturer specifications for different wire types and sizes.