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๐ NEC Chapter 2 Breakdown: Wiring & Protection Essentials
A guide to how power safely flows from service to device.
๐น Article 200 โ Grounded Conductor ID
Neutrals (#6 and smaller): Must be white, gray, or striped.
Larger than #6? You can tape or mark it at terminations.
๐ก Why it matters: Prevents misidentifying a neutral as a hot.
๐น Article 210 โ Branch Circuits
Covers receptacle spacing, GFCI/AFCI locations, and circuit sizing.
๐ก On site: Know your kitchen, bathroom, and exterior outlet rules cold.
๐น Article 215 โ Feeders
Feeders go from the main panel to subpanels.
Watch for ampacity, length derates, and disconnects.
๐น Article 220 โ Load Calcs
How to calculate service, feeder, and branch loads.
Required for panel sizing and avoiding overloading.
๐น Article 225 โ Outside Feeders
For feeders run outside but not part of the service.
Think conduits on rooftops, or shed panels.
๐น Article 230 โ Services
Where utility power enters the building.
Service entrance conductors, main disconnects, clearances.
๐น Article 240 โ Overcurrent Protection
Covers breaker and fuse sizing.
Key for tap rules, conductor protection, and short-circuit safety.
๐น Article 250 โ Grounding & Bonding
Probably the most cited article in the field.
Think: ground rods, equipment bonding, water pipe grounding, isolated grounds.
โ Why It Matters to You
If itโs wired, it better be protected.
If itโs metal, it better be grounded.
Chapter 2 makes sure both happen.
โ Quick Code Check
Choose the correct answer:
โ Question:
Youโre installing a sub panel 100โ away from the main. What do you check first?
A) Conduit fill
B) Voltage drop & conductor size
C) Lighting layout
D) Exit sign spacing
Answer below ๐
๐ง Think it through โ this conductor isnโt for carrying fault current, but to equalize voltage potential across all metal parts in and around the pool.
โ Answer: B) Voltage drop & conductor size (Articles 215 & 220 apply)
๐ Reference:
NEC 215.2(A)(1) & 220.61 โ These sections address feeder conductor sizing and load calculations, which are essential when installing sub-panels, especially at long distances where voltage drop becomes a key concern.
๐ Next Issue Preview:
Coming up: โThe 5 Things a Field PM Should Track Daily (But Often Doesnโt)โ