Quick Hits

Episode 2: Service & Load-Side Connections (705.11 – 705.13)

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: Interconnection Connections (Part 2 - Article 705) ⚡ 

Where do you tie in your distributed generation source? Article 705 spells out exact rules for connecting to a service or tapping into load-side distribution equipment. Let's break down the math! 👇

SLIDE 2 (LOAD-SIDE CONNECTIONS & THE 120% RULE) Busbar Tap & Backfeed Rules:

• The Busbar Limit: When connecting power sources to panelboard busbars without a specific listing for source combination, the sum of 125% of power source output currents plus the main OCPD rating cannot exceed 120% of the busbar ampacity (the classic 120% rule).

• Mandatory Warning Label: Must warn: POWER SOURCE OUTPUT. DO NOT RELOCATE THIS OVERCURRENT DEVICE.

SLIDE 3 (POWER CONTROL SYSTEMS - PCS) Smart Overload Protection:

• Using a listed Power Control System (PCS) allows electronic monitoring of multiple sources to actively control currents and prevent busbars or feeder conductors from being overloaded.

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

Service-side connections inside buildings under 705.11 require unprotected power source conductors to be kept short—within 10 feet for dwellings or 16.5 feet for commercial installations (unless under engineering supervision).

💬 Save this post for your next solar panelboard calculation! 🔗 

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