Solar System Size Calculator
Calculate AWG wire gauge, voltage drop, circuit breaker ratings, conduit fill, and electrical load requirements.
Input Parameters
Enter details for calculation.
Recommended Spec
Expert Tip
The National Electrical Code (NEC) recommends a maximum voltage drop of 3% for branch circuits and 5% total for combined feeder and branch circuits.
Calculation Methodology & Details
Formula
Applies National Electrical Code (NEC Table 8) circular mil area and copper conductor resistivity formulas.
Important Disclaimer
The calculations provided are for educational and preliminary planning. Always consult a Master Electrician and adhere strictly to local NFPA 70 / NEC electrical codes.
How to Calculate Step-by-Step
Follow these steps to complete the calculation:
Step 1
Select circuit nominal voltage (120V, 240V, 208V, or 480V three-phase).
Step 2
Input continuous current load in Amperes and one-way wire distance in feet.
Step 3
Calculate minimum AWG wire size, maximum conduit fill percentage, or breaker size rating.
Detailed Insights & Expert Guide
ℹ️ About this Calculation
The Solar System Size Calculator assists electrical contractors, engineers, and DIYers with sizing conductors, circuit breakers, conduit fill, and backup generator capacities in compliance with NEC safety standards.
Variable Glossary
Electrical Load
Circuit current in Amps, power in Watts, or running distance in feet.
Conductor Gauge
American Wire Gauge (AWG) size or overcurrent protection rating (Amps).