Safety engineering guidelines Pneumatic and electric solutions SLS STR STR STO SS1 STO SDI SS2 SOS v v v v v M s s s 0 t 0 t 0 t 0 t 0 t 0 t SDI SLP SSLPR SSR SSR SS2 v v v s s M vs v s 0 t t t t t 0 t 0 t SBC SLP SS1 STO SS2 SOS SOS SLS v v v v v s s s s M 0 t 0 t 0 t t t 0 t SBC Overview of technical safety measures Input Logic Input Logic Emergency stop Two-hand operation: Moving guard: safety door • Wiring • Safe, pneumatic solution Safety shut-off • Safety relay • Safety PLC Initial position, standstill Light curtain Set-up and Normal service operation operation Laser scanner Emergency operation Enabling switch Operating mode OFF selector switch Vision system Please observe the legal information on page 76. 2 Output Output Pneumatic Electrical SLS Safely limited Reducing speed v speed (SLS) 0 t Reducing pressure and force exhausting STO Safe torque off Exhausting v (STO) 0 t Safe direction SDI of movement Reversing the v s (SDI) movement 0 t Stopping, SS1 STO Safe stop 1 v holding, s (SS1) blocking 0 t SS2 SOS Safe stop 2 v s (SS2) 0 t SOS Stopping, Safe operating v holding, s stop blocking 0 t (SOS) SLP Safe position SPF s (SLP) t Protection against unexpected start-up You will see these symbols frequently on the following pages. They clearly and quickly point to the respective safety function. 3 Your partner for safety Quality has many aspects at Festo, one of which is working safely with machines. This has led to our safety-oriented automation technology. These components ensure that optimum safety is achieved in the workplace. This brochure is intended as a • What safety measures are drives, as well as the guide. It covers the core derived from these? corresponding solutions from questions relating to safety- • What are the most common Festo. These can be used to oriented pneumatics and safety measures? implement many safety electrical engineering: functions. Simple and helpful: • Why use safety-orientated The directives and standards are If you require more information, pneumatics? dealt with in the first part of the our specialists worldwide will be • How can I identify the risk brochure. The second part offers happy to help. posed by a system or machine an overview of the most to the operator or user? commonly used safety • Which standards and directives functions in connection apply? with pneumatic and electric Contents Introduction ....................................................................................... 5 Directives and standards .................................................................... 5 Safety functions through products and solutions ............................. 27 • Pneumatics ..........................................................................27 • Servopneumatics ................................................................. 55 • Electrical components ......................................................... 60 • Application and programming examples ............................. 66 Training and consulting .................................................................... 70 4 Reduce risk – think preventively Machines have to be designed in a way that protects people, animals, property and the environment from harm. The objective is to prevent physical damage of any type. Using safety-oriented pneumatic and electrical components from Festo provides you with the security of implementing safety measures that are compliant with the EC Machinery Directive. This reliably prevents collisions The safety objectives are Safety-oriented solutions from In addition to this, if faults occur, or uncontrolled restarts after an achieved using various safety Festo provide you with proposals they must not lead to failure of emergency stop, for example. At functions. for the safety functions, depending the same time, using safety- • Commissioning on their hazard potential. oriented pneumatics also Safety-oriented solutions in the • Automatic/manual operation minimises the risk of liability form of • Setting up claims. • Components • Risk situations and emergency • Circuits functions, such as safe The EC Machinery Directive • Engineering stopping, safe exhausting. 2006/42/EC specifies a risk make it easy to achieve your • Restarting -> protection against analysis and assessment for safety objectives. Reliable unexpected start-up machines. These have helped to operation of machines should be • Servicing/maintenance develop and define safety possible in all modes and stages objectives. of their service life. Simple but safe As a general rule, the simpler the As a result, it would seem safety technology used in the virtually impossible to implement application, the more efficient it standardised safety engineering is. The complexity of safety concepts. engineering is in the variety of state combinations and Due to their flexible application, transitional states. drive systems need to be included in the risk analysis and assessment for each machine, depending on the application. 5 Technical safety conditions There are legal requirements globally to ensure that machinery can be built and operated safely. Almost all laws require a risk assessment which reveals risks and results in risk minimising measures. Laws, e.g. EU Machinery Directive Objective: safe machines 2006/42/EC Risk assessment Objective: standardised process + "check list" Risk analysis Risk assessment Risk reduction Design measures Technical measures User information Safety function Objective: risk reduction Input Logic Output EN ISO 13849-1 IEC 61508/61511/62061 Objective: evaluation and assessment of technical safety measures Festo solutions Festo Evaluation: Objective: evaluation whether risk reduction is sufficient Festo Didactic: Training and Consulting Training Didactic: Festo PL ≥ PLr SIL ≥ SILr 6 Basic safety requirements in the manufacturing industry At the same time as the development of the single European market, the directives for machine construction in the manufacturing industry were harmonised. Free movement of goods within Europe Article 95 of the EU Treaty Article 137 of the EU Treaty (free movement of goods) (safety and health at work) "Safety and Health" Framework Directive e.g. machines 89/391/EEC EC Machinery "Use of work equipment" Low Voltage Directive Directive single directive 2006/95/EC 2006/42/EC 86/655/EEC Harmonised European standards National legal provisions Responsibility Manufacturers Operators Directives are comparable with the Machinery Directive. manufacturers. laws. Among others, the EC Harmonised standards provide Machinery Directive is applicable support for compliance with the for machine construction. The EC Machinery Directive. These primary aim of the EC Machinery are listed in the Official Journal of Directive is to specify basic the European Communities. health and safety requirements Applying these results is what is in relation to the design and known as the "presumption of construction of machines. The CE conformity", which reinforces the mark indicates compliance with legal security of operators and 7 Basic standards for designing control functions Harmonised standards that relate to machine safety help to reduce safety risks to an acceptable minimum, as per the EC Machinery Directive. Design and risk assessment of machinery Electrical safety aspects EN ISO 12100 EN 60204-1 Safety of machinery Safety of machinery General principles for design Electrical equipment of machines, Part 1: General requirements Functional and safety-oriented requirements for safety-related control systems Designing and implementing safety-related control systems EN 62061 Safety of machinery Functional safety of electrical/electronic/programmable safety-related electronic control systems Any architectures Safety integrity level (SIL) SIL 1, SIL 2, SIL 3 DIN EN ISO 13849-1 Safety of machinery Safety-related parts of control systems, Part 1 – General principles for design Designated architectures (categories) Performance level (PL) PL a, PL b, PL c, PL d, PL e 8 Definition of risk Risks are the result of hazards and relate to the gravity of possible damage and the probability of the damage Low risk High risk occurring. safety Risk limit Danger Residual risk Risk without safety measures Required minimum risk minimisation Actual risk reduction Safety = accepted residual risk Risk Severity Probability that damage in terms of the respective = of the possible damage + will occur hazard Frequency and duration of exposure to the hazard Options for avoiding or limiting the damage Probability of an event that could cause the damage occurring 9 Risk assessment Directives and standards describe the risk assessment process. All manufacturers are obligated to perform a risk assessment. This is followed by a risk evaluation and appropriate risk reduction measures must be implemented as required. Focusing on risk reduction Start This guide is primarily concerned Identifying/examining the with the area of risk reduction in Determine the limits of the system limits the form of technical safety machine • Limits of use • Space limits • Preliminary hazard Source: measures. We assume that all • Time limits analysis (PHA) EN ISO 12100 possible design measures for • "WHAT IF" method • Failure mode and effects Determine/define reducing risk have already been Determine hazardous analysis, failure effects states & transitional states explored. situation analysis (FMEA) Source:Source: • Failure simulation for Risk analysis EN ISO 12100 control systems Source: EN ISO 12100 • MOSAR procedure • Human intervention • Fault tree analysis;