# Solar Voltage Drop — NEC 210.19 Vdrop

> NEC 210.19 Vdrop (iPhone/iPad app by Rizvan Adzhoian.)

- Source: https://appshunter.io/ios/app/solar-voltage-drop/id6767838672 (this page in markdown: same URL + `.md`)
- Developer: [Rizvan Adzhoian](https://appshunter.io/developer/1891746079)
- Category: Utilities, Business
- Price: $0.99 with in-app purchases
- Age rating: 17+
- Requires: iOS 13.0 · 34 MB
- Languages: American English
- Released: 2026-05-11
- Data updated: 2026-09-08
- User reviews in markdown: https://appshunter.io/ios/app/solar-voltage-drop/id6767838672/reviews.md

## What is Solar Voltage Drop?

Solar Voltage Drop Calculator helps solar installers and electricians verify wire sizing for voltage drop compliance per NEC standards.

Supports DC solar circuits (NEC 690.31, 2% threshold) and AC branch circuits (NEC 210.19, 3% threshold). Choose from AWG 14 through 4/0, copper or aluminum conductors, and DC, AC single-phase, or AC three-phase circuits.

Features:
- Voltage drop in volts and percentage
- End voltage calculation
- Pass/Fail indicator based on NEC thresholds
- Automatic wire size recommendation when current selection fails
- Save calculations to history
- Export professional PDF reports
- NEC Chapter 9 Table 8 resistance data

Formula: VD = (multiplier x L x I x R) / 1000
- multiplier: 2 for DC/single-phase, 1.732 for three-phase
- L = one-way distance (ft)
- I = current (A)
- R = resistance (ohms/1000ft) from NEC Chapter 9 Table 8

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 the calculator:
- Unlimited saved calculation history
- PDF export of results
- Dark theme
- Ad-free experience

## Pricing and in-app purchases

Base price: $0.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Pro Unlock | $2.99 | one-time |



## Version history (last 3 releases)

### 1.0.2 — 2026-06-14

- Added larger conductor sizes: 250, 300, 350, 400, and 500 kcmil (copper and aluminum) for bigger AC and DC runs.
- Resistance values follow NEC Chapter 9, Table 8.
- Minor stability improvements.

### 1.0.1 — 2026-05-14

- Fixed cross-app links: tapping another SolarTools app in More Tools now opens its App Store page on iPhone and iPad.
- Minor stability improvements.

### 1.0.0 — 2026-05-11

No release notes.

## More apps by Rizvan Adzhoian

- [Conduit Fill Calculator-NEC](https://appshunter.io/ios/app/conduit-fill-calculator-nec/id6761846849)
- [Electrical Load Calc NEC](https://appshunter.io/ios/app/electrical-load-calc-nec/id6763250945)
- [Transformer Calc NEC](https://appshunter.io/ios/app/transformer-calc-nec/id6763311943)
- [Voltage Drop Calc NEC](https://appshunter.io/ios/app/voltage-drop-calc-nec/id6763312448)
- [Grounding Size Calc NEC](https://appshunter.io/ios/app/grounding-size-calc-nec/id6763312724)
- [Breaker Size Calc NEC](https://appshunter.io/ios/app/breaker-size-calc-nec/id6763312865)

All apps by Rizvan Adzhoian: https://appshunter.io/developer/1891746079

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-08.*