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 — fast, accurate calculations right at the job site. No internet required. No subscription. No fluff.

VOLTAGE DROP CALCULATOR

• Calculate wire size by distance or check voltage drop by wire size
• 1-Pole, 2-Pole, 3-Phase Line-to-Line, 3-Phase Line-to-Neutral, and DC systems
• OESC Appendix D3 compliant with accurate voltage drop factors
• Automatic parallel conductor options with OESC Rule 12-108 enforcement
• OPD sizing with one-tap breaker size selection
• Bonding conductor sized automatically with every calculation
• Maximum wire run length displayed for every result
• Power factor and installation method adjustments
• Temperature rating selection (60°C, 75°C, 90°C)
• 2%, 3%, 5%, or custom voltage drop targets

WIRE SIZE CALCULATOR

• Wire sizing based on OESC Table 2 and Table 4
• Copper and aluminum conductors
• Multiple temperature ratings (60°C, 75°C, 90°C)
• Derating factors for temperature and conduit fill
• Clear next size up recommendations

CONDUIT FILL CALCULATOR

• OESC Table 6 and Table 9 wire areas
• All raceway types (EMT, PVC, Rigid, DB2)
• Mixed wire sizes supported
• 40% and 53% fill rule compliance
• Instant minimum trade size recommendations
• Contingency allowance in percentage or mm²

BONDING CONDUCTOR CALCULATOR

• OESC Table 16 lookups
• Size from wire or from OPD rating
• Copper and aluminum bonding conductors
• Wire and bus bar output options
• Clear code reference citations

SAVE, ORGANIZE & EXPORT

• Save multiple calculations per session
• Organize work into projects — access from any calculator or the home screen
• Long press any saved calculation to preview, duplicate, rename, or delete
• Export professional PDF schedules for voltage drop and conduit fill
• Share PDFs via email, print, or save to files

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
• NO SUBSCRIPTION — One app, all features

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.