What should be ensured before operating folding machines?

Before operating folding machines, it is essential to ensure that hands are away from clamps. This safety precaution is critical because folding machines typically involve moving parts that can exert significant force and pose a risk of injury. Ensuring hands are clear of any clamps or other operational areas minimizes the possibility of pinching or crushing accidents during the machine's operation.

While the other options also pertain to safety considerations, they do not directly address the immediate risk associated with the folding machine's operation. For example, having the power supply turned off is important for maintenance or setup, but it must be on for the machine to operate. Disconnecting from the air source is relevant when maintenance is being performed, but during actual operation, the machine needs to be connected to function. Although wearing gloves can offer hand protection, they can also pose a hazard if they get caught in moving parts, making it critical to prioritize hand placement awareness first when operating the machine.