What type of wiring does Article 398 cover?

Article 398 of the National Electrical Code specifically covers "Open Wiring on Insulators." This type of wiring typically involves conductors that are supported by insulators, allowing them to be mounted on objects such as poles or building structures without the use of conduit or raceways. The intent of the regulations under this article is to ensure safety and reliability by specifying installation methods, splicing requirements, and other installation practices that mitigate risks such as electrical hazards or physical damage to the conductors.

Open wiring provides adequate spacing and support to avoid contact with conductive materials and is designed to protect the wiring from environmental factors. Understanding the context of this wiring type is crucial for anyone involved in electrical installations, as it has unique considerations in terms of compliance with safety standards.

Other options mentioned, such as messenger-supported wiring or surface nonmetallic raceways, refer to different types of electrical systems and installation methods, highlighting the diversity of electrical installations covered under various articles of the NEC.