What is the maximum allowable voltage in a machine room?

• A. 480 volts
• B. 600 volts
• C. 720 volts
• D. 1000 volts

Answer: (B)

The maximum allowable voltage in a machine room is set at 600 volts. This limit is established to ensure safety and minimize risks associated with high voltage equipment in confined spaces such as machine rooms, which typically house elevator equipment and controls.

At a voltage level of 600 volts, electrical components can be safely maintained and serviced while still providing enough power for operational needs. Voltages above this level, such as 720 or 1000 volts, could pose increased hazards for technicians working in close proximity to electrical equipment, raising the potential for electrical shock and maximizing the difficulties in managing and maintaining systems safely.

Thus, 600 volts is both a practical and safety-focused standard that aligns with industry practices to protect personnel working in or around elevator machine rooms.