PositionServo drives have a safety circuit that disables the drive output to the motor so that the drive cannot generate torque in the motor.
January 14, 2010 – Lenze-AC Tech announces the ISO 13849-1 Safety Circuit for the PositionServo drive. PositionServo drives with suffixes “ES” and “RS” now include a safety circuit that disables the drive output to the motor so that the drive cannot generate torque in the motor. This safety function, termed “Safe Standstill,” meets the requirements of ISO 13849-1 Safety of machinery -- Safety-related parts of control systems -- Part 1: General principles for design. The PositionServo ISO 13849-1 safety circuit provides a highly reliable disable of the drive. Even in the event of a single fault (single component failure) the ISO 13849-1 safety circuit will still function and disable the drive.