According to the NEC, live parts of electric equipment operating at 50 volts or more must be guarded against what?

The National Electrical Code (NEC) emphasizes the importance of safety in electrical installations, particularly regarding live parts of equipment operating at 50 volts or more. The correct focus here is on guarding against accidental contact. This requirement is in place to prevent shock or electrocution, ensuring that individuals do not unintentionally come into contact with energized components.

Electric equipment operates at voltages that can be dangerous to human life. Consequently, measures must be implemented to mitigate these risks, which often includes the use of barriers or enclosures designed to prevent people from touching live parts. This principle is foundational in electrical safety and emphasizes the need for protective measures in electrical installations.

While other considerations such as overheating, physical damage, and measuring errors are important aspects of electrical safety and equipment design, they do not directly relate to the primary safety concern addressed by the NEC regarding live parts. Thus, guarding against accidental contact remains the main focus within the context of electrical safety regulations.