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Module 8 · NEC 690 & 705

NEC 690 & 705

NEC Article 690's key solar PV requirements — rapid shutdown, disconnects, conductor sizing, and grounding — plus NEC Article 705's load-side vs. supply-side interconnection methods and the 120% busbar rule.

Article 690 and Article 705 cover two different halves of a PV installation — the array itself, and the interface where that array's output joins the building's existing electrical system — and this module works through both in the order an AHJ plan reviewer actually checks them: rapid shutdown timing and voltage limits, disconnect requirements, the two-step 690.8 conductor and OCPD sizing calculation, grounding, and then the load-side vs. supply-side interconnection choice that culminates in the 120% busbar rule.

By the end of this module you should be able to run the 690.8 conductor-sizing calculation and the 705.12(B)(3) busbar-headroom calculation on a real panelboard the way a plan reviewer would, and know which one determines the other when a design's numbers do not fit.

Free related reading in this studio
→ NEC Article 690: Solar PV System Requirements for Electricians and Engineers→ Calculator: NEC 690 PV Array Current & OCPD→ Calculator: NEC 705 Interconnection Current Limit (120% Busbar Rule)

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