You're not alone in your frustration. You've hit upon a critical problem with relying solely on AI for complex calculations in regulated fields like electrical work. It's good that you're verifying the AI's answers; that's essential!Here's a breakdown of why AI apps struggle with this task and what your options are

Why AI Fails at Conductor Sizing (Currently)
Data Scarcity and Quality

While AI can be trained on massive datasets, truly clean and comprehensive NEC-compliant datasets for every possible scenario are difficult to come by. The NEC has layers of complexity, deratings, corrections, and specific exceptions that are hard to fully capture in a training dataset.

Contextual Understanding

The NEC isn't just about formulas; it's about application and interpretation. AI struggles with understanding the context of your specific installation. Is it a dwelling unit? Is it a continuous load? Is it a service entrance? These nuances dramatically impact conductor sizing and AI frequently misses them.

Lack of Real-World Feedback

AI thrives on feedback loops. Unless these AI apps are continuously being fed verified real-world electrical installation data and receiving corrections, they won't improve quickly.

The NEC is Constantly Changing

The NEC is updated every three years. An AI trained on the 2020 NEC will be increasingly less accurate as time goes on and the code evolves.

Why You're Right to Build Your Own Spreadsheet

A spreadsheet, built from first principles (V=IR, etc.) is the most reliable approach, if you fully understand the NEC requirements and how to apply the formulas and tables correctly.

Reliable Software and Apps

Instead of AI-only apps, look for software and apps specifically designed for electrical calculations that have been developed and maintained by reputable companies in the electrical industry. These typically include: Electrical Calculation Software

Companies like Eaton, Schneider Electric, and Siemens offer software packages that incorporate NEC tables and calculation methods. These are typically more expensive but far more reliable. Often these include short circuit, coordination, and arc flash calculations.

Reputable Calculation Apps



Accubid

(Trimble) This is a more comprehensive estimating software suite but includes robust electrical calculation tools.

i-PDB

This app is specifically for calculating panel board loads and sizing feeders.

Key Features to Look for in Electrical Calculation Software/Apps



Regular Updates

Make sure the software/app is actively maintained and updated to the latest NEC version.

NEC Table Integration

The ability to directly reference and utilize NEC tables within the calculations.

Derating and Correction Factors

Automatic application of derating and correction factors for temperature, conduit fill, and other conditions.

Voltage Drop Calculation

Accurate voltage drop calculations based on conductor characteristics, load current, and distance.

Material Library

A comprehensive library of conductor types, sizes, and properties.

Documentation and Support

Clear documentation explaining the calculation methods and assumptions used.

When Will AI Be Trained on the NEC Code?

The future will likely bring more reliable AI for NEC calculations. Here's what needs to happen: Curated, High-Quality Datasets

The development of large, clean, and well-structured datasets that accurately represent the NEC, including all its nuances and exceptions.

Contextual Awareness

AI models that can understand the context of the installation (dwelling unit, commercial, etc.) and apply the appropriate rules.

Continuous Learning and Feedback

Mechanisms for AI to learn from real-world installations and receive feedback from experienced electrical professionals.

Explainability

The AI needs to be able to explain its reasoning and the steps it took to arrive at a particular conductor size. This is crucial for verification and trust.

In the meantime, here's my advice


Your Spreadsheet is a Good Idea

Develop your spreadsheet, double-checking all formulas and NEC references.2.

Use Reputable Software (If Possible)

Invest in a reputable electrical calculation software package from a well-known company in the industry, if your budget allows.3.

Always Verify

Regardless of the tool you use (spreadsheet, software, app), always verify the results against the NEC and with your own experience.4.

Consider Consulting an Electrical Engineer: For complex or critical installations, consider consulting with a licensed electrical engineer.You're right to be skeptical of AI's current capabilities in this area. A healthy dose of skepticism and thorough verification are essential when dealing with electrical safety. Flag for review