2. Choice of protection methods and means

At the design stage, guards or protective devices should only be installed if the hazardous phenomena could not be eliminated by choosing intrinsic prevention safety measures.

In the case of machines in service, the user's main role is to install protective devices.

However, before considering the choice and adaptation of protective devices, it is essential to examine the various machine components or units whose operation is fundamental to ensuring safety. In particular, any malfunctions of actuators and/or preactuators likely to jeopardize the safety of operators must be rectified.

In fact, when safety is based on control or sensitive devices (two-hand controls, light curtains, etc.), only the correct operation and reliability of the start-up and shutdown devices can guarantee operator safety. The reliability of...