At what voltage level must exposed live parts of motors and controllers be guarded against accidental contact?

The correct answer indicates that exposed live parts of motors and controllers must be guarded against accidental contact at a voltage level of 50 volts. This standard stems from the National Electrical Code (NEC) which defines a threshold for safe exposure to electrical equipment. At voltages above 50 volts, the risk of electrical shock increases significantly, necessitating protective measures to ensure safety around electrical installations.

The regulation emphasizes the importance of insulation, barriers, or other types of guards for any parts that could be easily touched or come into accidental contact, thereby preventing any potential accidents that could lead to injuries. Safety standards aim to minimize electrical hazards, and recognizing 50 volts as a critical threshold aligns with established safety practices in the electrical industry.