Solar PV String Wire Sizing & Voltage Drop Calculator
Connecting roof/ground solar arrays to charge controllers over long distances. Sizes DC PV extension wire gauge (10 AWG, 8 AWG, 6 AWG) to ensure voltage drop stays below the 2% solar industry best practice limit.
Step-by-Step Derivation ▼ Show Steps
Calculations adhere to standard electrical engineering physics and National Electrical Code (NFPA 70) regulations.
Engineering Principles & Calculations
This calculator uses the exact mathematical relationships between PV String Voltage (Vmp), Short Circuit Current (Isc), One-Way Distance (ft/m), Target Drop (default 2%) to determine Recommended Solar Wire Gauge (AWG / mm²), Actual Voltage Loss (V & %). In practical installations, factors such as ambient raceway temperature, harmonic distortion, duty cycle continuous operation, and conductor impedance must be accounted for by a certified electrician.
Sizes DC PV extension wire gauge (10 AWG, 8 AWG, 6 AWG) to ensure voltage drop stays below the 2% solar industry best practice limit.
Typical Application & Industry Guidelines
Connecting roof/ground solar arrays to charge controllers over long distances.
Solar PV String Wire Sizing & Voltage Drop Calculator Benchmark Lookup Table
| Wire Gauge (AWG) | Max Distance @ 10A (2% Drop @ 120V) | Resistance per 1000 ft | Max Ampacity (90C PV Wire) |
|---|---|---|---|
| 12 AWG Copper | 48 Feet | 1.98 Ohms | 30 Amps |
| 10 AWG Copper | 77 Feet | 1.24 Ohms | 40 Amps |
| 8 AWG Copper | 122 Feet | 0.778 Ohms | 55 Amps |
| 6 AWG Copper | 195 Feet | 0.491 Ohms | 75 Amps |
| 4 AWG Copper | 310 Feet | 0.308 Ohms | 95 Amps |