NEC Article 440

NEC 440: Air-Conditioning and Refrigerating Equipment

Written by a licensed IBEW journeyman electrician  ·  Updated May 2026 ·  Reviewed for NEC accuracy

What This Article Covers

NEC Article 440 covers air-conditioning and refrigerating equipment. It is a specialized supplement to Article 430 — most of the rules use the equipment nameplate ratings instead of motor tables.

Key Requirements

  • Conductor sizing based on nameplate minimum circuit ampacity (MCA)
  • Disconnect within sight of the AC unit (440.14)
  • Short-circuit and ground-fault protection per nameplate maximum overcurrent protective device (MOCP)
  • Compressor branch-circuit selection current can be used in place of FLA
  • Multi-motor equipment uses 440.33 sizing rules

Common Field Applications

  • Wiring a residential 4-ton heat pump
  • Installing a packaged rooftop AC unit
  • Disconnect for a mini-split outdoor condenser

Common Mistakes & Inspection Failures

  • Using motor FLA tables instead of nameplate MCA
  • Oversizing breaker beyond nameplate MOCP
  • Missing or mislocating the disconnect

Related NEC Articles

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Frequently Asked Questions

What does NEC 440 cover?

NEC Article 440 covers air-conditioning and refrigerating equipment. It is a specialized supplement to Article 430 — most of the rules use the equipment nameplate ratings instead of motor tables.

What are the key requirements of NEC 440?

Key requirements include: Conductor sizing based on nameplate minimum circuit ampacity (MCA); Disconnect within sight of the AC unit (440.14); Short-circuit and ground-fault protection per nameplate maximum overcurrent protective device (MOCP). See the full requirements list on this page.

What are common mistakes with NEC 440?

Using motor FLA tables instead of nameplate MCA Oversizing breaker beyond nameplate MOCP Missing or mislocating the disconnect

Related Resources

Michael B. — IBEW Local 134 Journeyman Electrician

Michael B.

IBEW Local 134 Journeyman Electrician · Licensed Electrical Contractor

Michael is a licensed electrical contractor and IBEW Local 134 journeyman with years of field experience. He built Sparky AI after ChatGPT gave him wrong NEC code information on a job — costing him $800 in callbacks. Every answer in Sparky AI is verified against the actual NEC.