Safety sub-functions of the safety brake
The implementation of a safety function with brakes requires that the brake be applied on request. The safety function is activated when the brake is applied. The brake coil has to be de-energized and the energy stored in the brake coil reduced.
By adding a safety brake to a safe overall system, the following safety sub-functions can be implemented:
- SBA (Safe Brake Actuation)
- SBH (Safe Brake Hold)
The SBA and SBH safety sub-functions are defined by SEW‑EURODRIVE based on the standard EN 61800-5-2.
The implementation of the SBA and SBH safety sub-functions additionally require the safety sub-functions SBC and STO in the overall system, in accordance with EN 61800-5-2. For safety-related requests of the brake, SBC and STO ensure that the brake applies and that the drive does not generate a torque against the applied brake.
The SBC and STO safety sub-functions are not part of the brake and have to be additionally implemented in the overall safety system. The performance level (PL) of the SBC and STO safety sub-functions must at least meet the required performance level (PLr) of the application.
SEW‑EURODRIVE recommends to stop the drive using stop category 1 according to EN 60204-1 prior to activating the SBC and STO safety sub-functions.
