PERFORMANCE

LEVEL

Performance Level

The Machinery Directive defines the Performance Level (PL) in EN ISO 13849 Parts 1 & 2. The PL is used to indicate the safety of a function or component. The higher the PL, the safer and more reliable the function under consideration. The specified value for the performance level thus also has an effect on where a particular component may be used, since the PL must always be at least as high as the risk value at the point under consideration.

“Controls must be designed and constructed in such a way that hazardous situations do not occur. They must be designed and constructed in such a way that they can withstand the expected operating stresses and external influences.“
When designing the respective machine or system for safety in accordance with EN ISO 13849, two performance levels must always be calculated. On the one hand, the required PL must be determined, on the other hand the achieved PL as well.

1. The required performance level:

The risk assessment according to EN ISO 13849 works in a similar way as according to EN 954-1. It is evaluated by assessing the risk on the basis of the extent of damage, frequency and length of stay and the possibility of avoiding the hazard. Following the evaluation, the required performance level is determined.

2. The performance level achieved:

To calculate the achieved performance level, the design of the control system or safety components and the hazardous situation are considered. This evaluation depends on the control categories, the MTTF values and the values for the diagnostic coverage ratio (DC).

Foundry Service guarantees the application of these regulations in accordance with the Machinery Directive for all new production, modernization or modification of control systems.

We are happy to support and advise you on questions or problems, manufacturer-independent, to determine the performance level.

To what is a performance level applied?

Safety functions are performed by safety-related parts of a control system (SRP/CS). Example: Purchase of fi nished safety components

Determining the required performance level (PLr)

The required performance level (PLr) is determined using a risk graph.
It assesses the risk for a given entity against three criteria:

  • Severity of injuries:
    S1: minor injuries
    S2: serious injuries
  • Frequency and length of stay:
    F1: between rarely and more often
    F2: between frequent and continuous
  • Possibility of avoiding the hazard:
    P1: possible under certain conditions
    P2: hardly possible