BRITISH STANDARDSafety of machinery Ð The positioning of protective equipment in respect of approach speeds of parts of thehuman bodyThe European Standard EN 999:1998 has the status of aBritish StandardICS 13.110; | BS EN999:1999| Incorporating| Corrigendum No. 1|NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 999:1999National forewordThis British Standard is the English language version of EN 999:1998.The UK participation in its preparation was entrusted to Technical CommitteeMCE/3, Safeguarding of machinery, which has the responsibility to:Ð aid enquirers to understand the text;Ð present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed;Ð monitor related international and European developments and promulgate them in the UK.A list of organizations represented on this committee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled ªInternational Standards Correspondence Indexº, or by using theªFindº facility of the BSI Standards Electronic Catalogue.A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application.Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 14, an inside back cover and a back cover.The BSI copyright notice displayed throughout this document indicates when the document was last issued.Sidelining in this document indicates the most recent changes by amendment.This British Standard, having been prepared under the direction of the EngineeringAmd. No.DateComments10653Corrigendum No. 1August 1999Indicated by a sidelineSector Committee, was published under the authority of the Standards Committee and comes into effect on 15 March 1999BSI 08-1999ISBN 0 580 32158 4Amendments issued since publicationEUROPEAN STANDARDEN 999NORME EUROPE ENNEEUROPAÈ ISCHE NORMOctober 1998ICS Descriptors: safety of machines, accident prevention, work safety, control devices, safety devices, ports: openings, distance, safe service life, computation, minimum valueEnglish versionSafety of machinery Ð The positioning of protective equipment in respect of approach speeds of parts of the human bodySe curite des machines Ð Positionnement dese quipements de protection en fonction de la vitesse d'approche des parties du corpsSicherheit von Maschinen Ð Anfordnung vonSchutzeinrichtungen im Hinblick aufAnnaÈ herungsgeschwindigkeiten von KoÈ rperteilenThis European Standard was approved by CEN on 20 September 1998.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official version (Enlgish, French, German). A version in any other language made by translation under the responsibility pf a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.CENEuropean Committee for Standardization Comite Europe en de Normalisation EuropaÈ isches Komitee fuÈ r NormungCentral Secretariat: rue de Stassart 36, B-1050 Brussels1998 CEN All rights of expoitation in any form and by any means reserved worldwide for CEN nationalMembers.Ref. No. EN 999:1998 EForewordThis European Standard has been prepared byTechnical Committee CEN/TC 114, Safety of machinery,ContentsPagethe Secretariat of which is held by DIN.This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 1999, and conflicting national standards shall be withdrawn atthe latest by April 1999.It is a type B1 standard and is intended to be an accompaniment to the European Standards EN 292-1 and EN 292-2.This European Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s).For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this standard.According to CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United KingdomForeword 20Introduction 31Scope 32Normative references33Definitions44Methodology45General formula for the calculation of minimum distances66Calculation of minimum distances for electro-sensitive protective equipment employing active opto-electronic protectivedevices 66.1Direction of approach normal to thedetection zone 6Direction of approach parallel to the detection zone9Direction of approach angled to the detection zone9Dual position equipment107Method of calculating the minimumdistances for ground level trip devices 117.1General method 117.2Floor mounting 117.3Step mounting 118Two-hand control devices 11Annex A (informative) Worked examples 12Annex B (informative) Walking speeds and stride lengths13Annex ZA (informative) Clauses of this EuropeanStandard addressing essential requirements orother provisions of EU directives 140 IntroductionThe effectiveness of certain types of protective equipment described in this standard to minimize risk relies, in part, on the relevant parts of that equipment being correctly positioned in relation to the danger zone. In deciding on these positions a number of aspects will need to be taken into account, such as:Ð a need for the identification of hazards and an assessment of all the risks;Ð practical experiences of users including accident statistics and existing national standards;Ð the state of the art and possible future technical developments;Ð type of equipment to be used;Ð response times of protective equipment used; Ð time taken to ensure the safe condition of the machine following operation of the protectiveequipment, . to stop the machine;Ð bio-mechanical and anthropometric data of body parts;Ð path taken by body part when moving from the sensing or actuating means towards the danger zone; Ð the possible presence of a person between thedevice and the danger zone;Ð the possibility of undetected access to the danger zone.If these aspects are further developed the current state of the art, reflected in this standard, will be improved.1 Scope1.1 This European Standard provides parameters based on values for hand/arm and approach speeds and the methodology to determine the minimum distances from specific sensing or actuating devices of protective equipment to a danger zone.1.2 These specific devices are:Ð trip devices as defined in 3.23.5 of EN 292-1:1991 (specifically electro-sensitive protective equipment, including those used additionally to initiate operation, and pressure sensitive mats);Ð two-hand control devices as defined in 3.23.4 ofEN 292-1:1991 and covered by EN 574.NOTE For the purposes of this standard, hold-to-run controls, which are designed to be actuated with one hand, are not considered to be protective equipment.1.3 This standard gives guidance based on the assumption that the correct device has been chosen either by reference to the appropriate type C standard or by carrying out a risk assessment.1.4 The calculated distances, when implemented, will provide sufficient protection for persons against the risks caused by approaching a danger zone which generate any of the following mechanical hazards, such as:Ð crushing, shearing, cutting or severing, entanglement, drawing-in or trapping, friction or abrasion, stabbing or puncture and impact.Protection against the risks from mechanical hazards arising from the ejection of solid or fluid materials and non-mechanical hazards such as toxic emissions, electricity, radiation, etc., are not covered by this standard.1.5 The distances are derived from data that take into account population groups likely to be found in European countries and are consequently applicable to those groups.NOTE 1 If this standard is to be used for non-industrial purposes then the designer should take into account that these data are based on industrial experience.NOTE 2 Until specific data is available for approach speeds for children, this standard uses adult speeds and lower detection factors, where relevant, to calculate the distances that could be within the reach of children.1.6 This standard does not apply to protective equipment which is intended to be moved, without tools, nearer to the danger zone than the calculated distance, . pendant two-hand control devices.1.7 The minimum distances derived from this standard do not apply to protective equipment used to detect the presence of persons within an area already protected by a guard or electro-sensitive protective equipment.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard onlywhen incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies.EN 292-1:1991, Safety of machinery Ð Basic concepts, general principles for design Ð Part 1: Basic terminology, methodology.EN 292-2, Safety of machinery Ð Basic concepts, general principles for design Ð Part 2: Technical principles and specifications.EN 294:1992, Safety of machinery Ð Safety distances to prevent danger zones being reached by the upper limbs.EN 574, Safety of machinery Ð Two-hand control devices Ð Functional aspects, principles for design.EN 1050, Safety of machinery Ð Principles for risk assessment.EN 61496-1:1997, Safety of machinery Ð Electro-sensitive protective equipment Ð Part 1: General requirements and tests. (IEC 61496-1:1997)3 DefinitionsFor the purposes of this standard the following definitions apply. Other definitions are givenin EN 292-1 and EN 292-2.actuation (of protective equipment)physical initiation of the protective equipment when it detects movement of the body or a part of the bodyoverall system stopping performancetime or travel occurring from the actuation of the sensing function to the cessation of hazardous motion, or to the machine assuming a safe conditionbased on 0 of EN 61496-1:1997The overall system stopping performance comprises a minimum of two phases:T = t1 + t2whereT is the overall system stopping performance;t1 is the maximum time between the actuation of the sensing function and the output signal switching devices being in the off state;t2 is the maximum response time of the machine, i.e. the time required to stop the machine or remove the risks after receiving the output signal from the protective equipment. t2 is influenced by various factors, . temperature, switching time of valves, ageing of components.The relationship of t1 and t2 is given in Figure 1.t1 and t2 are functions of the protective equipment and the machine respectively, and are determined by design and measurement.a) Actuating of protective equipment b) Operation of protective equipment c) Elimination of riskFigure 1 Ð Relationship between t1 and t2detection capabilitythe sensing function parameter limit specified by the supplier that will cause actuation of theelectro-sensitive protective equipment (ESPE)3.4 of EN 61496-1:1997NOTE Symbol d is used throughout the standard.electro-sensitive protective equipment (ESPE)an assembly of devices and/or components, working together for protective tripping or presence-sensing purposes and comprising as a minimum:Ð a sensing device;Ð controling/monitoring devices; Ð output signal switching devices3.1 of EN 61496-1:19974 MethodologyFigure 2 provides a schematic representation of the methodology for determining the correct position of sensing or actuating devices of protective equipment using this standard, which is as follows.a) Identify the hazards and assess the risks(see EN 292-1 and EN 1050).b) If a type C standard exists for the machine, select one of the specified types of protective equipment from that machine-specific standard, and then use the distance specified by that standard.c) If there is no type C standard or if the type C standard does not specify any minimum distances, then use the formulae in this standard to calculate the minimum distance for the protective equipment selected. The selection of the appropriate type of protective equipment should be made in accordance with the relevant type A and type B standards.d) Incorporate the distance in the machine design. e) Ensure the device has been installed in such amanner that access to the danger zone will not bepossible without detection by the device.f) Check if the determined position will allow persons to be between the sensing devices of the protective equipment and the danger zone without being detected. In this case supplementary measures may be required depending on the risk.Figure 2 Ð Schematic of methodology5 General formula for the calculation of minimum distancesThe minimum distance from the danger zone shall be calculated by using the general formula (1).S = KT + C(1)whereS is the minimum distance in millimetres, from the danger zone to the detection point, line, plane or zone;K is a parameter in millimetres per second, derived from data on approach speeds of the body or parts of the body (see also annex B);T is the overall system stopping performance in seconds (see );Cis an additional distance in millimetres, based on intrusion towards the danger zone prior to actuation of the protective equipment.For worked examples see annex A.6 Calculation of minimum distances for electro-sensitive protective equipment employing active opto-electronic protective devicesUsers of this standard shall select and useelectro-sensitive protective equipment for a machine in accordance with the appropriate type C standard for that particular machine. If no type C standard exists, they shall undertake a risk assessment accordingto EN 1050.This clause considers three main applications based on the direction of approach to the detection zone1):Ð normal approach (see Figure 3); Ð parallel approach (see Figure 4); Ð angled approach (see Figure 5).Where it is foreseeable that any gaps adjacent to or within the detection zone of the electro-sensitive protective equipment will allow access to the danger zone then this should be taken into account in the correct positioning of the protective equipment and additional safeguards considered.Access to the danger zone by reaching over or round the electro-sensitive protective equipment, together with any other protective equipment and additional safeguards, shall be prevented.6.1 Direction of approach normal to the detection zone6.1.1 Electro-sensitive protective equipment employing active opto-electronic protective devices with a maximum detection capability of 40 mm diameterThe minimum distance from the detection zone to the danger zone shall not be less than that calculated using formula (2).S = KT + C (see clause 5) (1)whereK = 2 000 mm/s;C = 8(d 2 14 mm), but not less than 0;d is the detection capability of the device, in millimetres.i.e.:S = (2 000 mm/s 3 T) + 8(d 2 14 mm) (2)This formula applies for all minimum distances of S up to and including 500 mm. The minimum value of Sshall not be less than 100 mm.If S is found to be greater than 500 mm using formula (2), then formula (3) can be used. In this case theminimum value of S shall not be less than 500 mm.S = KT + C (see clause 5) (1)whereK = 1 600 mm/s;C = 8(d 2 14 mm), but not less than 0. i.e.:S = (1 600 mm/s 3T) + 8(d 2 14 mm) (3)Where it is foreseeable that electro-sensitive protective equipment employing active opto-electronic protective devices will be used in non-industrial applications,. in the presence of children, the minimum distance S calculated with formula (2) shall be increased by at least 75 mm. It shall be noted that in such cases formula (3) is not applicable.6.1.2 Electro-sensitive protective equipment employing active opto-electronic protective devices used for reinitiation of machine operationElectro-sensitive protective equipment employing active opto-electronic protective devices used for reinitiation of machine operation shall have a detection capability equal to or less than 30 mm, formula (2) (see ) shall apply, and the minimum distance S shall begreater than 150 mm.If the detection capability is equal to or lessthan 14 mm, formula (2) shall apply, and the minimumdistance S shall be greater than 100 mm.NOTE 1 Conditions for using electro-sensitive protective equipment in the reinitiation of machine operation are given in EN 292-1 and EN 292-22) and relevant type C standards.NOTE 2 Additional requirements for electro-sensitive protective equipment are given in EN 61496-1.1) Definition see EN 61496-1.2) These requirements are under preparation and will be contained in the revision of EN 292-1 and EN 292-2.a) b)S) Minimum distance1) Danger zone2)