Quick Hits

Episode 2: Overcurrent Protection & Element Subdivision (424.22)

SLIDE 1 (HOOK / COVER)

⚡ NEC Quick Hit: Overcurrent Protection & Subdivision (Part 2) ⚡

The 60-ampere protection rule, 48-ampere element subdivision limits, and supplementary OCPDs—let's check Section 424.22! 👇

SLIDE 2 (RESISTANCE ELEMENT PROTECTION)

Subdividing Large Heaters:

• 60-Ampere Ceiling: Resistance-type heating elements in electric space-heating equipment must be protected at not more than 60 amperes.

• Subdivision Mandate: Equipment rated more than 48 amperes must have its heating elements subdivided so that each subdivided load does not exceed 48 amperes.

SLIDE 3 (SUPPLEMENTARY OCPDS)

Access and Requirements:

• Location & Access: Supplementary OCPDs for subdivided loads must be factory-installed within or on the heater enclosure (or provided as a separate assembly by the manufacturer) and must be accessible.

• Branch-Circuit Protection: Supplementary OCPDs must be suitable for branch-circuit protection.

SLIDE 4 (WRAP-UP) 💡 Apprentice Pro-Tip: 

When installing commercial electric space heaters rated over 48 amps, verify that internal supplementary OCPDs properly subdivide the loads into 48-amp maximum segments protected at 60 amps or less!

💬 Save this post for your next commercial heating installation!

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