Study Guides

Electrical Theory & NEC Code, Explained

Free in-depth guides covering electrical theory, NEC code articles, HVAC fundamentals, and exam concepts — with fully worked examples.

All Guides EPA 608 & HVAC Explained

EPA 608 & HVAC Explained

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Refrigerant certification rules, HVAC electrical systems, and EPA regulations explained in plain English for EPA 608 and HVAC exam candidates.

EPA 608 & HVAC Explained

EPA 608 Refrigerant Certification Explained

A plain-English guide to EPA Section 608 refrigerant certification -- the Core exam, the four certification types (Type I, II, III, Universal), recovery vs. recycling vs. reclamation, venting rules, leak repair requirements, and six real-world technician scenarios.

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EPA 608 & HVAC Explained

Air-Conditioning and Refrigeration Equipment Circuits Explained — NEC Article 440

A plain-English walkthrough of NEC Article 440 -- why hermetic compressor circuits are sized differently from ordinary motors, how to read RLA/LRA/MCA/MOCP off an equipment nameplate, and five fully worked examples for branch-circuit, overcurrent, and disconnect sizing.

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