Quick Hits
Quick Hits
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📁 Article 120
📁 Article 120
Branch-Circuit, Feeder, and Service Load Calculations
Branch-Circuit, Feeder, and Service Load Calculations
2026 NEC Quick Hits
A collection of short Quick Hits exploring load calculations, controlled loads, power control systems, noncoincident loads, and related requirements.
Article 120 of the 2026 NEC is where electrical systems get sized with real-world logic instead of guesswork. This article covers how to calculate the total electrical load for branch circuits, feeders, and services so that equipment like panels, conductors, and main breakers are properly rated for the job.Instead of assuming every load runs at full capacity at the same time, Article 120 introduces structured methods using unit loads, demand factors, and noncoincident load rules. This allows electricians to design systems that are both safe and practical, reflecting how buildings actually use power.From lighting and receptacles to HVAC and large appliances, Article 120 ties everything together into one complete load calculation system. The final result determines service size, feeder sizing, and overall system capacity.In short: NEC 120 is the blueprint for turning electrical loads into properly sized, code-compliant systems that won’t fail under real operating conditions.
⚡ QUICK HITS
⚡ QUICK HITS
↳ Understanding Load Calculations
↳ The Rules Behind Every Load Calculation
↳ What Are Noncoincident Loads?
↳ Break Your Calculations Down Into Buckets
↳ Heating and AC Load Buckets Part 2
↳ Adding Load to an Existing Dwelling
↳ Who Gets to Use the Dwelling Shortcut
↳ Small Appliance and Laundry Circuit Load Calculations
↳ The Fastened-in-Place Appliance Discount
↳ The Freestanding Range Table
↳ Big Ranges Get a Kilowatt-by-Kilowatt Bump
↳ Single Appliances Combo Circuits
↳ Commercial Kitchens Get Their Own Table
↳ Everything Else Gets Added On
↳ Allowable Demand Factors Finale
↳ Welcome to Part IV: Optional Calculations in the NEC
↳ The Neutral Conductor Finale
↳ Offices and Hotel Rooms Service Calculation
↳ Offices and Hotel Rooms Once Again
↳ Not All Lighting Gets Treated Equally
↳ Not All Lighting Gets Treated Equally
↳ Show Windows and Track Lighting
↳ Non-Dwelling Receptacles Get a Bulk Discount
↳ This Article Punts to Other Articles
↳ Using REAL Data Instead of Math
↳ Two-Unit Buildings Get a Sneaky Comparison
↳ Multifamily Buildings: The 3-Condition Checklist
↳ The Multifamily Demand Factor Table
↳ Schools Get Their Own Sliding Scale
↳ Farm Buildings: 60 Amp Tiers
↳ Combining Every Farm Building Into ONE Total Load
↳ A Whole Different Calculation System
↳ The Bigger the Park, the Bigger the Discount
↳ RV Parks: Every Site Gets a Starting Number
↳ Shore Power Gets Its Own Discount Curve
↳ Shore Power Gets Its Own Discount Curve Part 2
↳ Patient Care Circuits Get Their Own Rule Too
↳ Hospital Receptacles Get Their Own Discount Table
↳ When a PCS Monitors Everything
↳ When a PCS Controls Only Its Loads
↳ Controlled vs. Noncontrolled Loads
↳ How PCS Changes Load Calculations
📚 ARTICLE 120 RESOURCES
📚 ARTICLE 120 RESOURCES
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⚠️ Educational NoticeQuick Hits are educational explanations based on my understanding of the NEC. Always verify requirements in the current adopted NEC, applicable local amendments, manufacturer instructions, and with the AHJ.
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