1. What is a Portable Generator Size Calculator?

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

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Generator size (kilowatts)
• \( P_{load} \) — Total load power (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 expansion.

3. Importance of Proper Generator Sizing

Details: Correct generator sizing ensures reliable power supply, prevents overload damage, and improves fuel efficiency.

4. Using the Calculator

Tips: Enter the total wattage of all devices you need to power and a safety factor (default 1.2). The safety factor must be ≥ 1.

5. Frequently Asked Questions (FAQ)

Q1: Why do we need a safety factor?
A: The safety factor accounts for startup power surges (especially for motors) and potential future power needs.

Q2: What's a typical safety factor?
A: For residential use, 1.2-1.3 is common. For commercial/industrial with motor loads, 1.5 may be more appropriate.

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

Q4: Should I consider starting watts vs running watts?
A: Yes, the safety factor helps account for this. Some motors need 2-3 times their running wattage to start.

Q5: What if I have three-phase equipment?
A: This calculator is for single-phase systems. Consult an electrician for three-phase generator sizing.