1. What is a Whole House Generator Calculator?

Definition: This calculator estimates the required generator power in kilowatts based on your total electrical load and a safety factor.

Purpose: It helps homeowners and electricians determine the appropriate generator size for whole-house backup power.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Generator power (kilowatts)
• \( \sum P_{load} \) — Total electrical load (watts)
• \( SF \) — Safety factor (typically 1.25 for residential)

Explanation: The total load in watts is converted to kilowatts (divided by 1000) then multiplied by a safety factor to account for startup surges and future expansion.

3. Importance of Proper Generator Sizing

Details: Correct generator sizing ensures reliable power during outages, prevents overload situations, and maximizes fuel efficiency.

4. Using the Calculator

Tips: Enter the total electrical load in watts and safety factor (default 1.25). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why do we need a safety factor?
A: The safety factor accounts for motor startup surges (which can be 3-5x running watts) and potential future electrical needs.

Q2: How do I find my total electrical load?
A: Sum the wattage of all appliances you want to power simultaneously, or consult an electrician for a professional load calculation.

Q3: When would I change the safety factor?
A: Use 1.25 for typical residential, 1.5 if you have many motor-driven appliances, or 1.1 for just essential circuits.

Q4: Should I round up the generator size?
A: Yes, generators are typically sold in standard sizes (e.g., 10kW, 15kW, 20kW) - round up to the nearest available size.

Q5: Does this include starting watts?
A: The safety factor helps account for starting watts, but for precise calculations, add starting watts of motor-driven appliances separately.