---
title: "NEC 690 Reference - Reviews, Revenue and Downloads in United States | Apple App Store"
description: "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 educati"
---

# NEC 690 Reference — United States
> 60 NEC articles + calculators

![NEC 690 Reference App Icon](https://is1-ssl.mzstatic.com/image/thumb/Purple221/v4/ad/e3/36/ade33605-1750-0506-d920-7f2221d4d8eb/AppIcon-0-0-1x_U007emarketing-0-11-0-85-220.png/434x0w.png)

**Developer:** [Rizvan Adzhoian](https://apptail.io/developer/rizvan-adzhoian-zsuKac)
**Category:** Utilities
**Rating:** N/A (0 ratings)
**Price:** $0.99
**Bundle ID:** com.solartools.nec690
**Store:** Apple App Store
**Country:** United States
**Version:** 1.1.1 (released 2026-05-14)
**Original Release:** 2026-05-12
**Languages:** English

**App Store Link:** [Download on Apple App Store](https://apps.apple.com/us/app/app/id6767839064)
**AppTail Page:** [https://apptail.io/app/nec-690-reference-BRSA/united-states](https://apptail.io/app/nec-690-reference-BRSA/united-states)

## NEC 690 Reference Description
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

## NEC 690 Reference Screenshots
- [Screenshot 1](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/f4/2f/19/f42f19e2-4b74-5b94-f0eb-575b06184eb0/01_calculator_empty.png/1290x2796.png)
- [Screenshot 2](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/84/77/ee/8477ee61-7a99-040e-dc15-5cec11892e2c/02_calculator_result.png/1290x2796.png)
- [Screenshot 3](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/63/fc/55/63fc5551-b3c0-9020-0b8b-db415143c06b/03_history.png/1290x2796.png)
- [Screenshot 4](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/d0/10/73/d0107362-c210-d68f-dc79-921d9b5865ad/04_settings.png/1290x2796.png)



## NEC 690 Reference In-App Purchases
| Item | Price |
|------|-------|
| Pro Unlock | $2.99 |




## NEC 690 Reference Available In
- [Portugal](https://apptail.io/app/nec-690-reference-BRSA/portugal)
- [United States](https://apptail.io/app/nec-690-reference-BRSA/united-states)

---

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