It’s High Time for Increased Safety
Brakes which have proven their worth millions of times contribute to risk minimisation acc. EN ISO 13849-1
Machine and system manufacturers must determine the required performance level for every risk area in their products in accordance with the standard EN ISO 13849-1, and fulfil this performance level using suitable protective measures. Risks are generated, for example, if vertical axes inadvertent ly sink. The mayr power transmission safety brakes, which have already proved their reliability millions of times in field applications, can play a major role in risk minimisation.
- ROBA-topstop brake systems guarantee maximum safety in vertical axes. They hold the axis in any position even if the servomotor has been removed.
The primary objective of the standard EN ISO 13849-1 "Safety of machines" is to avoid risks to people. As well as the deterministic examination of a risk area, probabilistic methods of approach must also be applied. This is one of the major changes to the previously used standard EN 954-1, which limits itself to the approach of structure, error tolerance and error recognition for functional safety. The standard EN ISO 13849-1 also stipulates an evaluation of the hardware reliability, the effectivity of the measures used to reveal errors and measures against common cause errors.
This comprises of finding answers to the following statistical questions. When is an error generated which poses a risk? The evaluation is based on a statistically assumed time in which the hardware will function error-free in terms of safety without chance failures. The second important question is: How high is the possibility that an error that has occurred is recognised and removed before an error results which poses a risk? Apart from that, the approach includes an appraisal of how effective the measures are which should prevent dangerous failures occurring due to a common cause.
System manufacturers must determine the required performance level PLr for each risk area, and then achieve this or even surpass it using suitable measures. Therefore, it must initially be determined how high the risk coming from a machine or system actually is. Using suitable measures, the risk must be reduced to an acceptable minimum according to the required performance level.
An extremely efficient measure is the use of an additional safety brake. It can generally also be integrated into existing systems. In this way, "old systems" can be brought up to the current standard of safety in a price-effective manner. Please observe that the brake is only one component and that the entire channel including controls and signal detection must be included in the approach when determining the performance level.