# NEC 690 Reference > 60 NEC articles + calculators Canonical page: [https://chrome-stats.com/d/id6767839064](https://chrome-stats.com/d/id6767839064) ## Overview - **ID:** `id6767839064` - **Platform:** Apple - **Type:** Apple app - **Status:** Available - **Publisher:** Rizvan Adzhoian - **Category:** Utilities - **Version:** 1.1.1 - **Last updated:** 2026-05-14 - **First published:** 2026-05-12 - **Size:** 33 MB - **Data as of:** 2026-09-03 - **Store listing:** [Apple App Store](https://apps.apple.com/us/app/nec-690-reference/id6767839064) - **Website:** [https://tradetools.dev/](https://tradetools.dev/) - **Privacy policy:** [https://tradetools.dev/privacy-policy.html](https://tradetools.dev/privacy-policy.html) ## Description Expanded with 60 NEC sections, 5 in-app calculators, 25 quiz questions, 10 worked examples, inspection checklists, and ampacity tables — fully offline. 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 ## Rankings - #1,197,811 — Overall ## Similar extensions and apps - [NEC Mastery](https://chrome-stats.com/d/id6720711044) — 4.80 / 5 - [Master Electrician License Ex](https://chrome-stats.com/d/id6763056723) - [QuickNEC: NEC Calculator](https://chrome-stats.com/d/id6758503497) — 1.00 / 5 - [Master Electrician Guide](https://chrome-stats.com/d/id6782430546) - [Electric Master: NEC Panel](https://chrome-stats.com/d/id6760935722) — 3.60 / 5 - [Electrical Code Guide 2026](https://chrome-stats.com/d/id1045750831) - [NEC Master Suite: Exam Prep](https://chrome-stats.com/d/id6762178401) - [Electrical Companion](https://chrome-stats.com/d/id6760791199) — 4.50 / 5 - [NEC Electrician Calc: VoltKit](https://chrome-stats.com/d/id6782881081) - [Sparky's Black Book](https://chrome-stats.com/d/id6770407622) — 5.00 / 5 - [NEC Exam Prep](https://chrome-stats.com/d/id6757428316) — 4.30 / 5 - [ElectricianCalc NEC Calculator](https://chrome-stats.com/d/id6763315320) --- Source: [Chrome-Stats](https://chrome-stats.com/d/id6767839064)