Which of the following is NOT a requirement specified in NEC Article 110?

The requirement regarding the visual appeal of electrical installations is not addressed within NEC Article 110. NEC Article 110 focuses primarily on the safety and functionality of electrical installations rather than aesthetic considerations. The article emphasizes proper installation conditions, protection against physical damage, and maintaining clearances for accessibility and safety, which are critical for ensuring the effectiveness and longevity of electrical systems.

In contrast, maintaining the condition of installations free from contaminants ensures that electrical equipment operates efficiently and safely. Protection of conductors from physical damage is essential for preventing hazards and maintaining circuit integrity. Clearance requirements above floors are vital for safe access and preventing obstruction or potential electrical hazards. These aspects directly relate to safety regulations that are the core of NEC standards, highlighting the importance of functionality and safety over aesthetic views in electrical installations.