Quick Hits

Episode 3: UPS Systems, System Grounding & PDUs (645.11 – 645.17)

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: UPS Systems, Grounding & PDUs (Part 3 - Article 645) ⚡ 

Uninterruptible power supplies (UPS), signal reference grids, and multi-panel power distribution units (PDUs)—let's check out Part II of Article 645! 👇

SLIDE 2 (UNINTERRUPTIBLE POWER SUPPLIES - UPS)

Isolating Backup Power:

• Disconnecting Batteries: UPS systems installed within an ITE room and their supply/output circuits must comply with remote disconnect rules (645.10).

• The disconnecting means must also disconnect the backup battery bank from its load!

SLIDE 3 (GROUNDING & POWER DISTRIBUTION UNITS)

Signal Reference Structures & PDUs:

• Equipment Bonding: All exposed non-current-carrying metal parts of an ITE system must be bonded to the EGC (or double insulated). Signal reference grids must also tie into the EGC.

• Multi-Panel PDUs: Specialized Power Distribution Units (PDUs) used for server racks are permitted to house multiple panelboards within a single cabinet if listed as ITE utilization equipment.

SLIDE 4 (WRAP-UP)

💡 Apprentice Pro-Tip: Power Distribution Units (PDUs) in data centers contain dozens of miniature circuit breakers in one enclosure. Because they are listed multi-panel assemblies, they make high-density server rack branch-circuit routing clean and compact!

💬 Save this post for your next server room electrical distribution layout! 🔗 

More code breakdowns and study tools at www.JoshTheSparky.com

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