1. What is Generator Sizing?

Generator sizing is the process of determining the appropriate wattage capacity needed for a generator to power all connected electrical loads with a safety margin. Undersizing can lead to overload while oversizing is inefficient and costly.

2. How Does the Calculator Work?

The calculator uses the generator sizing formula:

Where:

• \( P_{total} \) — Required generator size in watts
• \( \Sigma P_{loads} \) — Sum of all connected loads in watts
• 1.2 to 1.5 — Safety factor (20% to 50% margin)

Explanation: The safety factor accounts for startup surges, future additions, and ensures the generator isn't constantly running at full capacity.

3. Importance of Proper Generator Sizing

Details: Correct generator sizing ensures reliable power supply, prevents damage to equipment, improves fuel efficiency, and extends generator lifespan.

4. Using the Calculator

Tips:

1. Calculate the total wattage of all devices you plan to power simultaneously
2. Select an appropriate safety factor (1.35 is typical for most applications)
3. The result shows the minimum generator capacity needed

5. Frequently Asked Questions (FAQ)

Q1: What safety factor should I choose?
A: 1.2 for minimal margin, 1.35 for typical applications, 1.5 for critical systems or motors with high startup loads.

Q2: Should I include all appliances or just essentials?
A: Include only what you plan to run simultaneously. Prioritize essentials for smaller generators.

Q3: How do I account for motor startup surges?
A: Motors may require 3-5 times their running wattage at startup. Either use a higher safety factor or add the startup wattage separately.

Q4: What about three-phase vs single-phase generators?
A: This calculator provides total wattage. Phase configuration depends on your equipment requirements.

Q5: Should I round up to standard generator sizes?
A: Yes, generators come in standard sizes (e.g., 5kW, 7.5kW, 10kW). Always round up to the next available size.