Solar Conductor Ampacity Calculator

Calculate conductor ampacity with NEC derating for conduit fill, ambient temperature, and rooftop temperature adder.

Input Parameters

Results

--
Adjusted Ambient
C
--
Temp Correction Factor
--
Fill Derating Factor
--
Derated Ampacity
A
Note: NEC Table 310.15(B)(3)(c) adds rooftop temperature. Table 310.15(C)(1) for conduit fill. PV wiring on rooftops often requires 2+ size upgrades.

Reference

Adjusted Ambient = Ambient + Rooftop Adder Temp Factor = sqrt((90 - Adj Ambient) / (90 - 30)) Fill Factor: 4-6 cond = 0.80, 7-9 = 0.70 Derated Ampacity = Base x Temp Factor x Fill Factor