Wiring & Safety
Advanced
Wiring Your System Safely
A practical guide to solar wiring: proper gauge selection, fuses and breakers, grounding, and code compliance.
1-2 hours
Basic electrical knowledge
Wire Gauge Selection
Undersized wire causes voltage drop and heat. Use a voltage drop calculator and keep drop under 2-3%. For most home solar runs, 10 AWG to 6 AWG is typical depending on current and distance.
Overcurrent Protection
Every circuit needs protection rated just above the expected current. Use DC-rated breakers or fuses in the correct locations — between panels (string fuses) and at battery banks.
Grounding
Ground the system to protect against lightning and faults. Connect racking, panel frames, and equipment to a grounding electrode per your local code. Never ground the positive conductor of an ungrounded array.