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VD = I × R - How Calculate Voltage Drop

Voltage Drop Formula:

\[ VD = I \times R \]

amps
ohms
volts

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1. What is Voltage Drop?

Definition: Voltage drop is the reduction in voltage in an electrical circuit between the source and load.

Purpose: Calculating voltage drop helps ensure proper operation of electrical equipment and compliance with electrical codes.

2. How Does the Calculator Work?

The calculator uses Ohm's Law formula:

\[ VD = I \times R \]

Where:

Explanation: The voltage drop equals the product of the current and the resistance in the circuit.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical devices receive adequate voltage to operate efficiently and prevents excessive power loss.

4. Using the Calculator

Tips: Enter the current in amps and the resistance in ohms. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's an acceptable voltage drop?
A: Typically 3% for branch circuits and 5% for feeder circuits, but check local electrical codes.

Q2: How do I find the resistance of a wire?
A: Use the wire's resistivity (Ω/m or Ω/ft) multiplied by its length, or consult wire specifications.

Q3: Does voltage drop affect power consumption?
A: Yes, voltage drop represents power lost as heat in the conductors (P = I²R).

Q4: Can I use this for AC circuits?
A: This simple formula works for DC circuits. For AC, you need to consider impedance (Z) instead of just resistance.

Q5: How can I reduce voltage drop?
A: Use shorter wire runs, larger wire gauge, or reduce the current load on the circuit.

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