Automation24 – Your online-shop for automation technology!
User Guide for Automation24 models including: 957901130, Safety Light Curtains, 957901130 Safety Light Curtains, Light Curtains, Curtains
Hazards from machines lurk around almost every corner in manufacturing processes. A particularly high risk is posed by manual work and testing ...
Datalogic SG4 BASE safety light curtains | Automation24
File Info : application/pdf, 4 Pages, 940.81KB
DocumentDocumentAutomation24 Whitepaper Safety light curtains compact guide | 1 SAFETY LIGHT CURTAINS Usefulthingstoknow,selectionguide &installationtips Did you know that you need safety technology? Anyone who works with and on machines, automated systems or robots, is often not aware of the dangers involved. The potential impact on the health of all users can be devastating, however. As is so often the case, prevention is the best protection! The right safety technology is needed here. Why safety light curtains in particular are the best solution and what important selection criteria as well as installation information which needs to be taken into consideration can be found in this guide. Why is safeguarding hazardous points with safety light curtains relevant for you? Hazards from machines lurk around almost every corner in manufacturing processes. A particularly high risk is posed by manual work and testing stationssuchaspresses,cutting,bending andpunchingmachines.Withoutappropriateprotectivemeasures it can happen all too quickly that users come into contact with movingmachineparts.Theconsequences:cuts,bruises,fractures, sprains or even worse. Topreventthisfromhappeninginthefirstplace,reliable detection of fingers, hands and other limbs entering hazardous areas is essential. In this way, the shutdown of dangerous machine movementscanbeinitiatedautomatically.Safety light curtains are anidealsolutionforthis! Fig. 1: The risk of injury in manufacturing processes is very high. What are safety light curtains and how do they work? Safety light curtains are one of a range of optoelectronic safety sensors. They consist of a transmitter and a receiver unit and are similar in their operating principle to throughbeamlightbarriersfromthefieldofphotoelectricsensors,whichareusedin particularforpositiondetection. A safety light curtain transmitter transmits a multitude of light beams at defined distances to the receiver module. This creates a virtual and very close-meshed barrier to demarcate or secure hazardous areas. As soon as fingers, hands or other limbs penetratethisbarrierandinterruptthelightbeams,thehazardous movements can be automatically switched off. Fig2:Safetylightcurtainsconsistofatransmitter and a receiver unit. Example: Datalogic 957901130 - SG4-30-030-OO-OO-E Anotherimportantdifferencetostandard lightbarriersisthatsafetylightcurtains, as safety sensors, have corresponding safety technology and/or features to prevent unexpected failures. For example, they have redundant OSSD outputs that pass on switching states to corresponding safety controllers or safety relay modules. OSSD is the abbreviation for the full name ,,Output S ignal Switching Device". These outputs send out periodic test pulsestodetectpossibleshortcircuits.Inaddition,safetylightcurtainshave self-test functionsthatalsocounteractsystemfailure. continued > Automation24 Whitepaper Safety light curtains compact guide | 2 Usefulthingstoknow,selectionguide&installationtips < continued Whataretheselectioncriteriaforasuitablesafetylightcurtainforyourapplication? Theselectionofasuitablesafetylightcurtainisverysimple.Youonlyneedtoconsiderthesethree to four selection criteria: Criteria Descr Resolution Describesthedistance between the light beams. Thisdefineswhichpartofthebodycanbereliablydetected. Fingerprotection:14mm Handprotection:30mm Protection field height Stands for the height of the area to be protected by the safety light curtain. This depends on the sizeoftheaccessibledangerarea. Providesinformationabouttheinternal structure of the light curtain to safeguard against unex- pectedfailures.Adistinctionismadeinparticular between type 2 and type 4 safety light curtains (rarely type 3). The higher the type, the higher the Performance Protection type Level(PL)thatcanbemetaccordingtotheDIN EN ISO 12849 standard. Type 4 light curtains meet the requirements up to PLe. Nowadays,type4lightcurtainshaveestablished themselves as the standard and light curtains withlowertypesareincreasinglybeingdisplaced from the market. Range (optional) Describesthemaximumdistance between transmitter and receiver. However, the maximum range of most safety light curtains is usually so large that itonlyplaysaroleinveryfewapplications.Therefore,itisconsideredanoptional criterion. Emitter Operatingdistance Receiver Protectionfield Protectionfield height Resolution Statusdisplay Inactivezone Powerconnection Power&OSSDconnection Fig.3:Safetylightcurtain-structure&selectioncriteria There are other design features in which safety light curtains can differ.Theseinclude,forexample,anextremelynarrowtypeorthe eliminationofadead zone.However,thesefeatures arerelevant forveryfewindustrialapplications.Inmostcases,theuseof light curtains with standard functions is perfectly adequate. Safety light curtains vs. safety light grids Didyouknowthat?Itisnotuncommonforsafetylightcurtainsandsafetylightgridstobemisleadingly used as synonymous terms. This is a fallacy, however. Although outwardly they look very similar to each other, there are essential differenceswithregardtotheircharacteristics andsuitableareasofapplication. One of the most significant differences is the resolution. While lightcurtainscreateamultitudeoflightbeamsat a small distance, light grids usually create only two to four light beams spaced at significantly larger distances. This is due to the different purposes for which they are designed. While safety light curtains are used for finger and hand protection detection at hazardous locations, light grids are used for more extensive area protection, whereby body detection by means of fewerlightbeamsissufficient. Fig. 4 Safeguarding hazardous points with a safety light curtain continued > Automation24 Whitepaper Safety light curtains compact guide | 3 Usefulthingstoknow,selectionguide&installationtips < continued Safety light curtains vs. safety light grids Fig.5Areaprotectionwithsafetylightgrid Areasafeguardareoftenrelevantinlogistics applications.Inthis context, muting is also an important requested feature, which makes it possible to bridge light grids for a short time in order, for example, to move pallets out of the hazardous area without bringing system processes to a standstill. Immediately after the pallet transport, the light grid is reactivated to detect persons entering the danger zone again. Hazardous location safeguarding with light curtains does not requireamutingfunctioninmostcases,as transporting materials out of the danger zone is rarely necessary here. How do you install and test safety light curtains correctly? Beforesafetylightcurtainscanbeused,itisimportantthattheyarefirstinstalledcorrectlyandthattheirfunctionalityistested. Selecting the correct minimum distance A very important point is to maintain the correct minimum distancebetweenthelightcurtainandthehazardouslocation. Theregulationsforthisareclearlydefinedinthe standard DIN EN ISO 13855. Light curtain safety distance - calculation formula: S = K * (t1 + t2) + C S = min. safety distance K = approach speed t1=responsetimeofthelightcurtain t2=responsetimeofthemachineuntilstandstill C=maximumdistanceofundetectedmovementbehindlightcurtain K and C set the standard here. K as reaching speed = 2,000 mm/s, if result of this formula > 500 mm, K=1,600mm/s(walkingspeed)maybeused =Mindestsicherheitsabstand C equals 8 * (resolution (d) - 14 mm) i.e. when using a 14 mm light curtain, C = 0 mm, and with a 30 mm light curtain C = 128 mm The following formulas are derived from this: For light curtains with 14 mm resolution: S = 2,000 mm/s * (t1+t2) For light curtains with 30 mm resolution: S = 2,000 mm/s * (t1+t2) + 128 mm S A S = Minimum safety distance A = Hazardous zone Fig.6-Lightcurtainsafetydistance:accordingtoDINENISO 13855,aminimumdistancemustbemaintained continued > Automation24 Whitepaper Safety light curtains compact guide | 4 Usefulthingstoknow,selectionguide&installationtips < continued How do you install and test safety light curtains correctly? Anti-circumvention protection Whencorrectlyinstallingasafetylightcurtain,itisimperativethatlimbsenteringhazardousareasare detected without exception. The prerequisiteforthisisthecorrectselectionofthe appropriate protection field heightsothatitisnotevenpossibletoreach past the light curtain into the danger zone. Furthermore,itmustbeensuredthatnoonecanbe present behind the light curtainunnoticed.Ifthesafetydistanceinanapplicationneeds tobeverylarge,theadditionalinstallationofahorizontal light curtainisessential. Correct vs. impermissible mounting: Fig.7:Installationatalow safety distance Fig.7.1:Itmustnotbe possibletoreachpasta safety light curtain. Fig. 8: At a very high safety distance, the horizontal installationofasafetylight curtain is required. Fig. 8.1: An undetected stay behindthelightcurtainmust notbepossible. Alignment aid Since the light beams transmitted by the light curtain are not visible,aligningthetransmitterandreceiveroverlongerdistances canproveverydifficult. Laser pointers mountedonthetransmitter can help here. Daily function tests with test rods Totrustisgood,tocheckisbetter.Thisalsoappliestosafetylight curtains! To verify correct functionality and reduce the risk of liabilityintheeventofamalfunction,adaily function test of each safety light curtain is recommended. Vibration protection Safetylightcurtainsaredesignedtocausemachinestobeswitched offassoonasthelightbeamtransmittedbythetransmittercannot reach the receiver. However, this is a hindrance with strongly vibrating machines, as the vibration may cause the transmitter andreceivertobebriefly offsetfromeachother.Vibration-heavy applicationsthereforerequiretheuseof special vibration dampers to prevent false tripping. For this purpose, a test rod is passed through the protection field to check the correct interruption of the light curtain beams. The test rod must have the diameter of the resolution of the relevant light curtain. Protect yourself and your employees with light curtains You now know how important it is to have adequate point of operation guardingandwhysafetylightcurtainsinparticularare a great solution here. In many online shops you will find designs foreveryneedandbudget.Mostapplicationscanbecoveredwith basiclightcurtains.ForexampleAutomation24 offersanappealing rangefromDatalogicforstandardrequirements.Particularlygood prices and fast delivery capabilitiesgohandinhandwiththisoffer. Safetytechnologymustnotbealuxury.Donottakeyourhealth or the health of your employees lightly and insist on reliable safety light curtains for your protection! With this compact guidebook, you are now ideally prepared, to choose the right safety light curtain for your application and install it in accordance with the standards. +44 178 489 5006 00800 24 2011 24 (free) info@automation24.co.uk automation24.co.uk