EN 13849 - Safety Related Parts of Control Systems.
EN13849 provides a methodology for deciding what level of integrity the safety related control systems
on a machine should have and a methodology for calculating whether a control system meets the required level of
SafeMech has considerable experience in applying EN13849 to both design of new control systems and validation of
existing ones. We can help you work your way through the intially rather intimidating calculations and
requirements of this standard.
EN 13849 replaces the previous standard for Safety Related Control Systems for machinery EN954. EN954 provided a
simpler, more mechanistic approach to safety system integrity by specifying a particular architecture of control
system to meet a certain level of integrity. As control systems become more based on electronics and less on simple
relays and switches this approach becomes ever harder to apply.
EN13849 retains reference to the system architectures used in EN954 but applies a numerical reliability approach
to try to achieve a more scientifically justified approach.
Most control systems which met the requirements of EN954 can be shown to also meet the requirements of EN13849,
but in some cases, especially for systems which did not fully meet the requirements of EN954, improvements may be
It is important to remember that a control system approach to reducing risk is not the best. The ideal
approach is to eliminate the hazard by design in the first place. Next best if to take simple mechanical measures
such as fixed guarding. In machine safety, the simplest approach is nearly always the best!