NEC reference & solar calculators
NEC reference tables and calculators for residential solar and electrical design — the same deterministic tables OneLine Studio's compliance engine uses to size every conductor, breaker and grounding conductor.
Tables & calculators
- NEC 310.16 conductor ampacity table
- NEC 240.6(A) standard breaker & fuse sizes
- NEC 250.122 equipment grounding conductor sizing
- NEC 250.66 grounding electrode conductor sizing
- NEC 690.7 PV string sizing & maximum system voltage
- NEC 690.8 PV conductor & OCPD sizing
- NEC 705.12(B) — the 120% busbar rule
- Voltage drop tables for solar circuits
- Conduit fill for solar circuits
- Ambient temperature correction factors
Draft this design in minutes — free
Describe a residential solar + storage system in plain English. OneLine Studio drafts the one-line diagram, sizes the conductors, runs these NEC checks live, and builds a permit-ready package.
Start free →