Component designs to satisfy functional safety standards
Functional safety systems include electronics in the form of sensors, I/O, controls, switches, electromechanical components, fluid-power components, and software that detect dangerous conditions and change the machine state to prevent dangerous situations from arising.
Safety is a top priority in industrial applications to protect employees and equipment from injury and damage. Welding, cutting, and pressing operations as well as high-speed axes and those handling dangerous workpieces or substances pose the most threat. In the U.S., plant operators must satisfy Occupational Safety and Health Administration (OSHA) regulations with safe equipment, operational procedures, and training protocols. Complementing these systems should be plant-
dangerous situations from arising. First originating in the European Union, today functional-safety design and regulations apply to suppliers, machine builders, and end users around the world. The harmonized European Norm (EN) and International Electrotechnical Commission (IEC) EN/IEC 62061 standard — listed in EU Machinery Directive 2006/42/EC — and the International Organization for Standardization (ISO) EN/ISO 13849-1 standard are the most applied. ISO 13849-1 and IEC 62061 can be cross-referenced, and OEMs and end users are free to use either. The only caveat is that functional safety relates to machines and controls and not devices or components … though the latter may offer functionalities supporting the satisfaction of a given safety rating. EN/IEC 62061 details requirements and recommendations as safety integrity levels for the design, integration, and validation of permanently installed (nonportable) machine or plant-
Figure 1: Light towers today use LEDs for efficiency and visibility. Some enhance safety with built-in buzzers to emit a siren to 100 dB during safety breaches. (Image source: Menics)
Written by: By Lisa Eitel
Contributed By DigiKey's North American Editors
specific analyses to identify pragmatic ways to enhance
installation SRECS — consisting of s afety- r elated e lectrical, electronic, and programmable controls. EN/IEC 62061 safety integrity levels (SILs) grade a system’s functional safety from 1 (most rudimentary) to 4 (most integrated and sophisticated) with SIL3 the highest possible for machines. Risks dictating the required SIL include the regularity of risk exposure, severity of the potential injury, incidence probability, and likelihood that a machine operator’s evasive maneuvers can help avoid harm.
worker well-being and equipment longevity. In addition, automated machinery must satisfy functional safety requirements via automatic machine actions or corrections to potentially or certainly unsafe conditions or failures. Functional safety systems include electronics in the form of sensors, I/O, controls, switches, electromechanical components, fluid-power components, and software that detect dangerous conditions and change the machine state to prevent
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