Online Calculator – Performance Level
The determination of the performance level must be carried out for each safety function and without taking into account the risk reduction achieved thereby. This does not apply to technical safety measures that are independent of the controller. As an example, mechanically separating protective device can be mentioned here.
Tool for determining the performance level
Example definition of the performance level
On this page we would like to provide you with an exemplary determination of the performance level. We therefore hope to be able to remove any final ambiguities about the calculation.
Scenario: Lifting table in the workshop
In our example, the performance level is to be determined for a commercially available lifting table. This is used in a workshop to raise components to an ergonomically lower height. Due to its area of application, the lifting table has to perform relatively little lifting movements.
Step 1: Severity of injury
First of all, the severity of the injury in the event of a possible accident must be assessed.
In the present case, only a hazard arises when the lifting table is lowered. In the worst case, body parts could get into the scissors or between the platform and the base frame. Although lifting platforms are equipped with switch boards that prevent crushing between the platform and the base frame, they must not be taken into account when determining the performance level.
If a body part arrives during the lowering into the scissors, serious (irreversible) injuries are possible, for this reason S2 must be chosen.
Step 2: Frequency and duration of exposure
As mentioned earlier, the lifting table has to perform relatively little lifting movements. In addition, no gripping into the danger zone is necessary for the operation of the stage. Based on these requirements, F1 can be selected.
Step 3: Possibility to avoid hazard
In the event of damage, the platform of the lifting platform, without any special equipment, could be accelerated almost with the acceleration of the earth towards the base frame. However, lifting tables are equipped as standard with pipe breakage fuses, which prevent such a rapid lowering.
Since the functioning of the pipe breakage protection is based on mechanical principles, so it is not dependent on the control, they can be taken into account in the risk assessment.
By using pipe breakage fuses, people have enough time to move out of the hazardous area, so P1 can be selected.
For the present example, the path S2-F1-P1 is thus obtained. The technical device, which protects against crushing in the scissors or between the platform and the base frame, must therefore meet the performance level ‘c’.