Purpose of Grounding (Article 250 Overview)
NEC Article 250 is arguably the most important section of the Code for safety. Its primary goal is to protect people from electrical shock...
Proper Sizing of Conduits and Raceways. NEC Annex C.
NFPA 731 Section 4.6.3.12(2) clearly states that whenever raceways, conduits, or tubing are used (even for security systems), they must be sized in accordance...
Table 250.66 — Grounding Electrode Conductor Size
NEC Table 250.66 is the standard for determining the size of the Grounding Electrode Conductor (GEC) for alternating-current systems.
Grounding Electrode Conductor for Alternating-Current Systems
Use...
Table 310.15(B)(3)(a) — Adjustment Factors
Overview
When more than three current-carrying conductors are installed together in the same raceway, cable, or bundled group, their ability to dissipate heat decreases.
To prevent...
Table 310.16 — Ampacity of Conductors
Purpose
NEC Table 310.16 provides the allowable ampacity (current-carrying capacity) of insulated conductors rated 0 – 2000 volts.
It is one of the most used tables...
NEC Article 215 Feeders: Sizing, Protection & Rules Explained
NEC Article 215 explained: how feeders are sized (125% of continuous load), protected, grounded and identified, plus when ground-fault protection is required.
Branch Circuit Definition (NEC Article 210): Types and Ratings
A branch circuit is the wiring between the final breaker or fuse and the outlets. NEC definition, the 4 types, 10–50 A ratings, and the 80% load rule.
Article 200 — Grounded Conductors
Quick Answer
NEC Article 200 sets the rules for identifying and using grounded conductors, which in most systems means the neutral....
Article 110 – General Requirements for Electrical Installations
Purpose
Article 110 of the National Electrical Code® (NEC®) outlines the fundamental safety requirements for all electrical installations.
It ensures that equipment is installed, maintained, and...
NEC Article 100 Definitions: Key Terms Explained
NEC Article 100 is the code's dictionary: how definitions are organized and what key terms like bonding, grounded, service equipment and nominal voltage mean.
NEC Article 90: Purpose, Scope, Mandatory and Permissive Rules
NEC Article 90 explained: what the Code covers and excludes, who enforces it, and how to tell mandatory rules (shall) from permissive rules and notes.
