In a data processing room, where must the disconnecting means be located?

The disconnecting means in a data processing room must be located at the principal exit door to ensure that anyone leaving the room can quickly and safely access it in case of an emergency. This positioning allows for immediate disconnection of power to the equipment, reducing the risk of electrical hazards, such as electrocution or fire, in emergency situations.

This approach aligns with safety codes and standards that prioritize quick access to power controls when an area contains sensitive equipment or has a high potential for electrical incidents. By situating the disconnecting means at the principal exit, it provides a clear and designated location for individuals to disconnect devices if necessary, ensuring safety protocols are easy to follow in urgent situations.