1. What is a Portable Generator Size Calculator?

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

Purpose: It helps homeowners, contractors, and event planners determine the appropriate generator capacity for their power needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Generator size needed (kilowatts)
• \( \Sigma(P_{load}) \) — Total electrical load (watts)
• \( SF \) — Safety factor (typically 1.2-1.5)

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 supply, prevents overloads, improves fuel efficiency, and extends equipment life.

4. Using the Calculator

Tips:

• Sum the wattage of all devices to be powered simultaneously
• Use a safety factor between 1.2 (for resistive loads) and 1.5 (for motor loads)
• Consider both running watts and starting watts for motor-driven appliances

5. Frequently Asked Questions (FAQ)

Q1: Why is a safety factor needed?
A: It accounts for startup surges (especially for motors), future expansion, and ensures the generator isn't constantly running at full capacity.

Q2: What's a typical safety factor?
A: 1.2 for mostly resistive loads (lights, heaters), 1.3-1.5 for motor loads (refrigerators, AC units).

Q3: How do I find my total load?
A: Add the wattage of all devices you plan to run simultaneously. Check appliance labels or manuals for wattage information.

Q4: Should I consider starting watts?
A: Yes, especially for motor-driven appliances which can require 2-3 times their running wattage during startup.

Q5: Can I use this for whole-house generators?
A: The same principle applies, but consult an electrician for whole-house systems to ensure proper load balancing.