Size Wire for 20kW Generator

Wire Size Formula:

\[ A_w = \frac{I \times L \times K}{V_{drop} \times \sigma} \]

System Voltage (V):

Power Factor:

Wire Length:

Correction Factor (K):

Allowed Voltage Drop:

Conductivity (σ):

Ω⁻¹·mm²/m

Wire Cross-Sectional Area (mm²):

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1. What is a Wire Size Calculator for 20kW Generator?

Definition: This calculator determines the appropriate wire size needed for a 20kW generator installation based on electrical parameters.

Purpose: It helps electricians and engineers select the correct wire gauge to ensure safe and efficient power transmission from the generator.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ A_w = \frac{I \times L \times K}{V_{drop} \times \sigma} \]

Where:

\( A_w \) — Wire cross-sectional area (mm²)
\( I \) — Current (amps) calculated from 20kW power
\( L \) — Wire length (feet)
\( K \) — Correction factor (typically 1.25)
\( V_{drop} \) — Allowed voltage drop (volts)
\( \sigma \) — Conductivity of copper (58 Ω⁻¹·mm²/m)

Explanation: The formula calculates the minimum wire size needed to keep voltage drop within acceptable limits for the given current and distance.

3. Importance of Proper Wire Sizing

Details: Correct wire sizing prevents excessive voltage drop, reduces energy loss, and minimizes fire hazards from overheating.

4. Using the Calculator

Tips: Enter system voltage (typically 120V, 240V, or 480V), power factor (0.8-1.0), wire length, correction factor (default 1.25), allowed voltage drop (typically 3%), and conductivity (58 for copper). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is voltage drop important?
A: Excessive voltage drop can cause equipment to malfunction or operate inefficiently.

Q2: What's the typical power factor for generators?
A: Most generators operate at 0.8 power factor unless specified otherwise.

Q3: When would I change the correction factor?
A: Adjust for different installation conditions (e.g., 1.0 for short runs, higher for long runs or bundled wires).

Q4: How do I convert mm² to AWG?
A: Use a wire gauge chart to find the nearest standard AWG size that meets or exceeds the calculated mm².

Q5: Does this calculator work for aluminum wire?
A: For aluminum, change conductivity to 36 Ω⁻¹·mm²/m and select appropriate wire gauge.