1. What is Panel Size Calculation?

The panel size calculation determines the minimum electrical panel capacity needed to safely handle a given electrical load, following the National Electrical Code's 80% rule for continuous loads.

2. How Does the Calculator Work?

The calculator uses the 80% rule formula:

Where:

• \( Total\ Load \) — Sum of all connected electrical loads in amps
• \( 0.8 \) — Safety factor (80% rule) to prevent overloading

Explanation: The 80% rule means a circuit should not continuously carry more than 80% of its rated capacity.

3. Importance of Proper Panel Sizing

Details: Correct panel sizing prevents overheating, reduces fire risk, ensures reliable operation, and meets electrical code requirements.

4. Using the Calculator

Tips: Enter the total connected load in amps. The value must be greater than 0. The calculator will determine the minimum panel size needed.

5. Frequently Asked Questions (FAQ)

Q1: Why use the 80% rule?
A: The 80% rule provides a safety margin for continuous loads (3+ hours) to prevent overheating and circuit breaker tripping.

Q2: What's the difference between main panel and subpanel?
A: Main panels connect directly to the utility service, while subpanels are fed from the main panel. Both need proper sizing.

Q3: How do I calculate total load?
A: Sum the amperage of all connected devices, considering both continuous and non-continuous loads.

Q4: What about future expansion?
A: Many electricians recommend adding 20-25% capacity beyond current needs for future circuits.

Q5: When should I consult an electrician?
A: Always consult a licensed electrician for panel upgrades, as improper installation can be dangerous.