# Volt Drop Check & Plug — Voltage Drop & NEMA/IEC Guide

> Voltage Drop & NEMA/IEC Guide (iPhone/iPad app by MASAHIRO HIRAIWA.)

- Source: https://appshunter.io/ios/app/volt-drop-check-and-plug/id6752117109 (this page in markdown: same URL + `.md`)
- Developer: [MASAHIRO HIRAIWA](https://appshunter.io/developer/1814993082)
- Category: Utilities, Productivity
- Price: $0.49 (on sale, was $3.99)
- Age rating: 4+
- Requires: iOS 15.1 · 35 MB
- Languages: American English
- Released: 2025-09-12
- Data updated: 2026-09-07
- User reviews in markdown: https://appshunter.io/ios/app/volt-drop-check-and-plug/id6752117109/reviews.md

## What is Volt Drop Check & Plug?

Volt Drop Check & Plug is an iPhone-only electrical calculation toolkit for field electricians, maintenance technicians, and design engineers. Stop juggling paper tables, calculators, and spreadsheets — switch between tabs and get the answer you need in seconds.

■ What's inside

1) Voltage Drop Calculator
• Inputs: supply voltage, load current (or power in W), cable length, conductor material (copper / aluminum), insulation (PVC 70°C, XLPE 90°C, heat-resistant PVC 105°C), circuit type (DC / 1-phase 2-wire, 3-phase 3-wire), power factor, and optional reactance.
• Outputs: ΔV, drop %, terminal voltage, loop resistance, and assumed conductor temperature.
• GOOD / CAUTION / NG verdict badge with a one-line explanation, improvement suggestions, risk notes, and basis notes.
• Round-trip ×2 applied automatically for DC / single-phase; √3 factor applied for three-phase.

2) Cable Size Selection (reverse calculation)
• From load current, voltage, cable length, allowable drop %, material, circuit type, power factor, and ambient temperature, get the minimum required conductor area and a recommended cable size.
• Side-by-side comparison of common sizes with PASS / FAIL / BEST indicators.

3) Ampacity Calculator
• From conductor material, size, installation method (free air / in conduit / bundled), insulation type, ambient temperature, and grouping count, see base ampacity with temperature and grouping correction factors.
• Corrected ampacity plus a per-installation-method summary.

4) Breaker Selection Guide
• From circuit current, circuit voltage, usage (general load / motor / lighting / IT·server), and phase (single / three), get a recommended rating (AT), frame size (AF), and type (MCCB / MCB / ELCB).
• Earth-leakage (ELCB) recommendation is highlighted automatically where appropriate. Includes a type guide.

5) Power Calculator (W ↔ VA ↔ kVA ↔ var)
• Convert between active power (W / kW), apparent power (VA / kVA), reactive power (var / kvar), and phase angle φ from voltage, current, and power factor.
• Three input modes: V×A, W, or VA. Single-phase / three-phase switchable.

6) NEMA / IEC Plug Quick Reference
• A searchable cheat sheet for plugs and connectors — useful for overseas sites and imported equipment. Filter by code, voltage, and more.

■ Designed for the field
• One-tap Japanese / English UI toggle (selection is remembered).
• All calculations run on-device — works reliably even with poor signal.
• Clear separation of inputs and results, with verdict badges and plain-language notes.
• iPhone-first layout tuned for one-handed use.

■ Great for
• Field electricians and contractors
• Facility and maintenance technicians
• Plant and building-services engineers
• Solar, energy-storage, and EV-charging designers
• Teams working with imported or overseas equipment
• Electrical students and trainees

■ Important
Results are reference values based on generic targets (e.g., 3% voltage-drop goal, 5% maximum). Always follow your local codes, internal standards, and equipment specifications for actual design and installation.


## Version history (last 2 releases)

### 1.2.0 — 2026-04-25

Improved usability
Significant enhancements to various features

### 1.0 — 2025-09-12

No release notes.

## Apps similar to Volt Drop Check & Plug

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [dB Meter-Decibel  Sound Level](https://appshunter.io/ios/app/db-meter-decibel-sound-level/id1629575835) | — | Free | Utilities |
| [IRith.io](https://appshunter.io/ios/app/irithio/id6741703900) | — | Free | Utilities |
| [超シンプル電圧降下計算](https://appshunter.io/ios/app/id6760455127) | — | Free | Utilities |
| [第四北越　通帳アプリ](https://appshunter.io/ios/app/id1455925982) | — | Free | Utilities |
| [Voltage Drop Calculator.](https://appshunter.io/ios/app/voltage-drop-calculator/id1203737064) | 4.6 (412) | Free | Utilities |
| [BONIQ remote](https://appshunter.io/ios/app/boniq-remote/id1492431115) | 2.0 (1) | Free | Utilities |

## More apps by MASAHIRO HIRAIWA

- [Rackviz](https://appshunter.io/ios/app/rackviz/id6746072022)
- [IP Calc(ipv4/ipv6)](https://appshunter.io/ios/app/ip-calcipv4ipv6/id6746962545)
- [RackPlanner Pro](https://appshunter.io/ios/app/rackplanner-pro/id6746972550)
- [Clarity Calc](https://appshunter.io/ios/app/clarity-calc/id6749896438)
- [Visual TCPIP Trainer](https://appshunter.io/ios/app/visual-tcpip-trainer/id6752111554)

All apps by MASAHIRO HIRAIWA: https://appshunter.io/developer/1814993082

---

*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 2026-09-07.*