1. What is a Home Generator Size Calculator?

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

Purpose: It helps homeowners and professionals determine the appropriate generator capacity for backup power needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

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

3. Importance of Proper Generator Sizing

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

4. Using the Calculator

Tips: Enter the total wattage of all appliances you want to power and a 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 power needs.

Q2: How do I find my total load?
A: Add up the wattage of all appliances you want to power simultaneously. Check appliance labels or manuals for wattage information.

Q3: When would I change the safety factor?
A: Use 1.5 for heavy motor loads (well pumps, AC units) or 1.1 for only lighting and small electronics.

Q4: Should I include every appliance?
A: Include only essential appliances you need during an outage. Prioritize refrigerators, heating/cooling, medical equipment, etc.

Q5: Does this include startup surges?
A: The safety factor helps account for surges, but for large motors, you may need to calculate startup watts separately.