1. What is a Whole House Generator Calculator?

Definition: This calculator determines the total generator capacity needed by summing the running watts of all appliances and adding the largest starting watts requirement.

Purpose: It helps homeowners and electricians properly size a whole house generator to ensure all essential appliances can run simultaneously.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Total Watts — Required generator capacity (watts)
• Running Watts — Sum of all appliances' continuous power needs
• Starting Watts — Highest surge wattage from any single appliance

Explanation: The total running watts represent continuous load, while the maximum starting watts accounts for the largest momentary surge when an appliance starts.

3. Importance of Proper Generator Sizing

Details: Correct sizing prevents generator overload, ensures reliable operation during outages, and extends equipment lifespan.

4. Using the Calculator

Tips:

• List all essential appliances and their running watts
• Identify which appliance has the highest starting watts
• Enter the sum of running watts and the maximum starting watts

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between running and starting watts?
A: Running watts are continuous power needs, while starting watts are temporary surges (typically 2-3x running watts) when motors start.

Q2: Should I include all appliances in my home?
A: Include only essential appliances you want to power during an outage. Prioritize refrigerators, HVAC, medical equipment, etc.

Q3: How do I find appliance wattage?
A: Check appliance labels, manuals, or use a wattage meter. Many appliances list running amps which can be converted to watts (Watts = Volts × Amps).

Q4: Should I add a safety margin?
A: Yes, consider adding 10-20% to the calculated total for future additions and to avoid running at maximum capacity.

Q5: What if I have multiple large motors?
A: If multiple high-starting-watt appliances might start simultaneously, sum their starting watts rather than just taking the maximum.