In the National Electrical Code (NEC), Article 240 specifically addresses overcurrent protection. Overcurrent protection is crucial to prevent damage to conductors and equipment due to excessive current flow in electrical circuits. Here's an overview of key points from NEC Article 240:
Scope and Application: Article 240 outlines the general requirements for overcurrent protection devices and their application in various electrical systems.
Device Types: The NEC provides guidance on the types of overcurrent protection devices, including fuses, circuit breakers, and other approved devices, and their suitability for different applications.
Rating and Setting: The article specifies the proper selection of overcurrent protection device ratings, considering factors such as conductor size, load characteristics, and the specific requirements of the electrical system.
Coordination: NEC Article 240 emphasizes the importance of coordination between overcurrent protection devices within a system. Coordinated protection ensures that the device closest to the fault clears the fault first, minimizing unnecessary disruptions.
Ground-Fault Protection: The NEC addresses the need for ground-fault protection in certain circuits and systems to enhance safety by quickly detecting and clearing ground faults.
Overcurrent Protection for Conductors: The article provides guidelines for protecting conductors against overcurrent, taking into account the conductor size, temperature rating, and insulation type.
Tap Conductors: NEC Article 240 includes provisions for tap conductors, specifying the conditions under which taps are permitted, the maximum length allowed, and the necessary overcurrent protection.
Multiple Feeder Taps: The article outlines rules for multiple feeder taps from a single source, addressing conditions under which such arrangements are acceptable and the associated overcurrent protection requirements.
Electrical professionals, including designers, installers, and inspectors, should reference NEC Article 240 to ensure that overcurrent protection is appropriately applied in electrical systems. This helps promote electrical safety, prevent equipment damage, and ensure compliance with national electrical codes and standards.
