Quick Hits

Episode 4: Circuit Conductors & Room Air Conditioners (Parts IV & VII)

SLIDE 1 (HOOK / COVER)

⚡ NEC Quick Hit: Conductors & Room Air Conditioners (Part 4) ⚡

The 125% rule, wye-start delta-run exceptions, and mandatory LCDI/HDCI cord protection—let's finish Article 440! 👇

SLIDE 2 (CONDUCTOR SIZING & MULTIMOTOR LOADS)

Carrying the Current (Part IV):

• Single Motor-Compressor: Branch-circuit conductors supplying a single motor-compressor must have an ampacity of not less than 125 percent of either the FLC or the branch-circuit selection current, whichever is greater.

• Wye-Start Delta-Run: Conductors between the motor controller and compressor for wye-start, delta-run configurations are permitted to be sized at 72 percent due to internal winding current splits.

SLIDE 3 (ROOM AIR CONDITIONERS & CORD SAFETY)

Window Units and Cords (Part VII):

• Single Unit Rules: Cord- and plug-connected room air conditioners rated up to 40 amps and 250V single-phase are treated as single motor units.

• Mandatory Cord Protection: Single-phase cord- and plug-connected room air conditioners must feature a factory-installed leakage-current detector-interrupter (LCDI), arc-fault circuit interrupter (AFCI), or heat-detecting circuit interrupter (HDCI) integrated directly into the plug or within 12 inches of it.

SLIDE 4 (WRAP-UP)

💡 Apprentice Pro-Tip: Never bypass or modify factory-installed LCDI or HDCI cords on room air conditioners—these specialized cords prevent thermal and shock hazards caused by damaged storage cords or overheating compressors!

💬 Save this post for your final code review on Air-Conditioning & Refrigeration!

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