According to company sources, 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.
Dale Seidlitz, Quality and Safety Manager at Lenze-AC Tech, states that the ISO 13849-1 addresses safety circuits in programmable electronic systems, providing the customer with one more safeguard to protect his investment in automation equipment and personnel. "ISO 13849-1 uses probability to define performance levels in terms of category (structure), mean time to dangerous failure (MTTFd), diagnostic coverage (DC) and common cause failure (CCF), says Seidlitz, and he continues, "Fully characterizing those four parameters provides a clearer picture of the level of performance required for the safety circuit to disable the device in which it is installed. "
Explaining that Lenze-AC Tech drives are employed in many types of automated processes worldwide and the safety of both the equipment and personnel is paramount. Seidlitz comments, "Designing our products in accordance with the strict requirements of international safety standards just makes it easier for our global customers to purchase them."
Lenze-AC - www.lenze-actech.com
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