# Guiomar Field Electrical Tools > Guiomar Field Electrical Tools (iPhone/iPad app by Carlos Pimenta.) - Source: https://appshunter.io/ios/app/guiomar-field-electrical-tools/id6757681183 (this page in markdown: same URL + `.md`) - Developer: [Carlos Pimenta](https://appshunter.io/developer/1868112350) - Category: Utilities - Price: Free - Age rating: 4+ - Requires: iOS 16.0 · 19 MB - Languages: American English - Released: 2026-01-26 - Data updated: 2026-05-14 - User reviews in markdown: https://appshunter.io/ios/app/guiomar-field-electrical-tools/id6757681183/reviews.md ## What is Guiomar Field Electrical Tools? GUIOMAR Field Electrical Tools is a professional electrical calculator app designed specifically for Ontario electricians working with the Ontario Electrical Safety Code (OESC) 2024. Built by an electrician for electricians - this app delivers fast, accurate calculations right at the job site. No internet required. No subscription. No fluff. WIRE SIZE CALCULATOR - Wire sizing based on OESC Table 2 and Table 4 - Copper and aluminum conductors - Multiple temperature ratings (60C, 75C, 90C) - Derating factors for temperature and conduit fill - Clear next size up recommendations VOLTAGE DROP CALCULATOR - DC, Single Phase, and Three Phase systems - OESC Appendix D3 compliant calculations - Parallel conductor support - Power factor adjustment - 3% and 5% threshold indicators CONDUIT FILL CALCULATOR - OESC Table 6 and 9 wire areas - All raceway types (EMT, PVC, Rigid) - Mixed wire sizes supported - 40% fill limit compliance - Instant minimum trade size recommendations BONDING CONDUCTOR CALCULATOR - OESC Table 16 lookups - Overcurrent protection device sizing - Copper and aluminum bonding conductors - Clear code reference citations WHY GUIOMAR? - 100% OFFLINE - Works in basements, mechanical rooms, anywhere - OESC 2024 COMPLIANT - Accurate to current Ontario standards - FAST - Get answers in seconds, not minutes - PROFESSIONAL - Clean interface designed for field use - NO ADS - Focus on your work, not interruptions Calculations are based on OESC 2024 tables and formulas. Always verify results against the Ontario Electrical Safety Code and consult with the Electrical Safety Authority (ESA) for code interpretations. The app is currently offered for free. Pricing and availability may vary by region and may change in the future. ## Version history (last 5 releases) ### 1.2.8 — 2026-03-15 What's New in GUIOMAR Field Tools Parallel Conductors — Wire Size Calculator High-amperage loads often require parallel runs. The Wire Size Calculator now lets you select 1, 2, or 3 conductors per phase before calculating. The app divides your load accordingly, finds the minimum wire size per conductor from OESC Tables 2 & 4, and displays the total ampacity of the parallel set — per Rule 12-108. Example: 800A load @ 75°C Cu 1 conductor → Exceeds table range 2 conductors → 2 × 600 kcmil Cu (420A each / 840A total) 3 conductors → 3 × 300 kcmil Cu (320A each / 960A total) Built by an electrician, for electricians. ### 1.2.7 — 2026-03-12 Removed USEI90 600V (Underground Secondary AL) and Southwire HV XLPE (69kV–345kV Transmission) cable types from the Conduit Fill cable library. These cable types are not relevant to typical conduit fill calculations and were removed to simplify the selection process. The library now focuses on TRXLPE MV (15kV–35kV) medium voltage cables. ### 1.2.6 — 2026-03-08 Version 1.2.6 — Conduit Fill: Cable Library & Custom Wire Entry What's New The Conduit Fill calculator now includes a built-in cable library and custom wire entry mode for real-world cable pulls beyond standard OESC wire tables. Cable Library Pick manufacturer cables directly by OD — no more looking up datasheets on site. Library includes: • Noramco, Nexans, Priority Wire & Cable — USEI90 600V aluminum underground secondary • Prysmian — TRXLPE 15kV through 35kV, aluminum and copper, 100% and 133% insulation levels • Texcan — TRXLPE/PVC concentric neutral, 15kV through 35kV copper • Southwire — HV XLPE 69kV through 345kV, corrugated and laminate sheath Custom Wire Entry Switch any wire to CUSTOM mode and enter the cable outside diameter (OD) in mm. Area is calculated as π × (OD ÷ 2)² per OESC Rule 12-910(4)(c). Bug Fixes & Improvements • Quantity dropdown removed from custom/library mode — MV and HV cables are always 1 per conduit • Standard wire entry unchanged ### 1.2.5 — 2026-02-19 Bug Fixes Fixed an issue where saving a calculation to a project would keep the calculator linked to that project — any new calculation after saving now starts fresh with no project attached Fixed saving to the wrong project after switching between projects Fixed duplicate circuits appearing when loading from a project ### 1.2.4 — 2026-02-19 Bug Fixes & Improvements Fixed: Loading a saved calculation from a project now saves directly back to that project — no more project selection dialog appearing when it shouldn't. Fixed: This applies to both Conduit Fill and Voltage Drop calculators when loading individual calculations from a project. Fixed: BOND info icon now displays correctly in the Voltage Drop results screen. --- *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 2026-05-14.*