1. What is a House Generator Watt Calculator?

Definition: This calculator estimates the wattage requirement for a whole-house generator based on your total electrical load and a safety factor.

Purpose: It helps homeowners and electricians properly size a backup generator to handle all essential electrical loads during a power outage.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_w \) — Required generator wattage (watts)
• \( \sum P_{load} \) — Sum of all electrical loads (watts)
• \( SF \) — Safety factor (typically 1.25 for residential)

Explanation: The total wattage of all appliances and systems is multiplied by a safety factor to account for startup surges and future expansion.

3. Importance of Proper Generator Sizing

Details: Correct wattage calculation ensures your generator can handle all essential loads without overload, while avoiding overspending on an unnecessarily large unit.

4. Using the Calculator

Tips: Enter the total wattage of all appliances/systems you want to power, and the 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 3-7x running wattage) and potential future electrical needs.

Q2: What's a typical safety factor?
A: Residential generators typically use 1.25, while commercial applications may use 1.5 or higher.

Q3: How do I find my total load wattage?
A: Sum the wattage of all appliances you want to power simultaneously, or use our Appliance Wattage Calculator.

Q4: Should I include every appliance?
A: Include only essential loads you'd need during an outage. Prioritize refrigeration, heating/cooling, lights, and critical medical equipment.

Q5: What about central air conditioning?
A: AC units require significant startup power. Consider their locked rotor amperage (LRA) when calculating total load.