When does a category 2 or category 4 device has to be used?
The EN-954-1 standard has been created to aid machinery manufactures in selecting the safety level necessary for the different machinery types. The standard is based on 3 fundamental parameters: the damage gravity that can be provoked, the frequency it can occur and the duration to the risk exposure of the operator and the possibility to avoid the danger. The combination of the three parameters defines the necessary safety category: a category 4 safety device has to be used in presence of high damage gravity, high risk frequency and exposure and non-avoidability.
