1)fail-safe system,元件有故障仍能工作的系统2)system malfunction,系统工作不正常[故障]3)fail safe,故障时仍能安全运行的<能>4)non-trouble work condition,无故障工作条件5)active fault,现有故障，起作用的故障6)fail-safe device,故障时(仍能)安全运行的自动保护装置
用法例句
This paper explores the design theory for the radius of cam base-round based on the non-trouble work condition of mechanism, and expounds the steps and means for seeking the radius of cam base-circle and the related parameters by using graph ways.
