NEC 690 Reference

About this app

NEC 690 Reference is a study and field companion for solar photovoltaic professionals working under the National Electrical Code Articles 690, 691, 705, 706, and 710. Everything is paraphrased educational summary — designed for quick lookups, exam practice, and inspection prep, fully offline. WHAT IS INSIDE - 60 NEC section summaries across Articles 690 (PV Systems), 691 (Large-Scale PV), 705 (Interconnection), 706 (Energy Storage), and 710 (Stand-Alone Systems) - 31 plain-language definitions of NEC terms (PV source circuit, PV output circuit, MPPT, rapid shutdown, AHJ, NRTL, qualified person, listed, labeled, and more) - 10 step-by-step worked examples with numbers and conclusions: cold-temperature Voc, PV source current sizing, voltage drop, conductor temperature derating, OCPD selection, conduit fill, inverter AC sizing, 120% rule, EGC sizing, breaker selection - 25 NABCEP-style practice quiz questions with explanations and NEC citations - 3 inspection checklists (pre-install, mid-install, final inspection) with 16+ checkpoints each, anchored to specific NEC sections - 4 quick reference tables: standard breaker sizes, copper ampacity (75 / 90 C), aluminum ampacity (75 / 90 C), and copper conductor resistance per 1000 ft - 13 code-change entries highlighting differences between NEC 2017, 2020, and 2023 for the major solar-related sections 5 IN-APP CALCULATORS - Cold-Temperature Voc — adjusts module Voc for the lowest expected ambient and reports the maximum string length under the inverter max DC voltage (NEC 690.7) - PV Source Circuit Current — applies the 1.25 x 1.25 factor for conductor and OCPD sizing (NEC 690.8 and 690.9) - Voltage Drop — AC single phase, AC three phase, and DC; copper or aluminum; AWG 14 to 4/0 - Conduit Fill — EMT, RMC, and PVC Schedule 40; THWN-2, XHHW-2, and PV Wire; warns when fill exceeds 40 percent - Breaker Size — selects the next standard NEC 240.6 ampere rating for continuous or non-continuous loads DESIGNED FOR - Solar PV installers and electricians - Electrical engineers and PV designers - Building inspectors and plan reviewers - Apprentices and NABCEP candidates studying for certification IMPORTANT All content is an original paraphrased educational summary. This app is not a substitute for the official NEC or any certification exam materials. Always consult the latest published NEC and the local Authority Having Jurisdiction for legal requirements. OPTIONAL PRO UPGRADE — $2.99 ONE-TIME IN-APP PURCHASE The following features require a separate one-time in-app purchase. They are not required to use any of the calculators or content above: - Unlimited article views with no daily limit - Dark theme - Ad-free experience Contact: support@tradetools.dev

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1. First observed Oct 16, 2026 · 4:59 PM $0.99