Quick Hits

🎬 NEC 2026 ARTICLE 120 SERIES
PART 4 OF 30 — NEC 120.7 | POWER CONTROL SYSTEMS (PCS)

NEC 120.7 EXPLAINED ⚡
HOW PCS CHANGES LOAD CALCULATIONS
joshthesparky4 · Josh The Sparky

⚡ OPENING HOOK

A Power Control System changes how you calculate loads...

But only if it meets strict NEC rules. ⚠️

🧠 CORE IDEA

⚡ A Power Control System (PCS) actively monitors electrical loads and controls equipment to prevent overload conditions.

Instead of assuming all loads operate at full demand simultaneously, the NEC allows PCS-managed systems to reduce calculated load values—under strict conditions.

Think of it as smart load control...

With Code enforcement behind it.

⚡ CODE CONNECTION

Before a PCS can be used in load calculations:

✅ It must comply with NEC Article 130 requirements
✅ Control settings must be established by qualified persons
✅ It must be properly listed, installed, and used per NEC rules

A PCS is NOT just automation.

It is a listed load management system with safety limits.

⚡ THE 80% RULE

PCS control settings are limited to:

⚡ 80% of the rating of the overcurrent protective device (OCPD)

Example:

🔌 100A breaker
⬇️
⚡ Maximum PCS setting = 80A

This ensures the system has a built-in safety margin before protective devices operate.

📌 CORE TAKEAWAY

⚡ PCS systems actively manage load demand.

⚡ They can only be used in calculations when properly listed and installed.

⚡ Control settings are limited to 80% of the OCPD rating.