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I have a question regarding perimeter safeguarding, or fencing. I remember in previous standard, that the requirement was to have 18" from the perimeter safeguarding to the programmed path of the robot in T1 APV. I don't see a similar requirement in the 2012 standard. What I do see is that it states that the perimeter safeguarding cannot be installed closer than the restricted space (5.4.2). Also, it states that perimeter safeguarding can the limiting device if it meets 5.4.3. Note 4 states that it can only be so if it does not have any hazardous deformations to the guard. So my questions are this: Is there something still in existence that looks at this from a T1 aspect of things and stipulates how far the fence needs to be from the operating space? Also, If I build my fencing to withstand a full force collision without hazardous deformation, can the fencing then be the restricted space? Thanks.
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Hello Scott. 1. The perimeter fencing can be the limiting device for restricted motion provided there is no hazardous deformation of the guard. Most perimeter guards simply cannot withstand the force of the main robot axis motion. 2. The minimum gap is no longer specified directly but you are referred in 5.1 of Part 2 to ISO 13854 for minimum gaps to prevent crushing. The required distance is 20 inches. Hope this helps.
Scott, Since RIA 15.06-2012 was created to conform to a world ISO standard, many of those distances have been adopted from ISO and are simply referenced in the RIA document. Answer 1: Restricted Space: "Portion of the maximum space restricted by limiting devices that establish limits which will not be exceeded" This definition was taken from ISO 8373:1994, Def 4.8.2. We are currently using a 20" clearance dimension between robot/eoat and guarding, after stopping times/distances (Calculate using ISO 13855) have been added. See RIA 15.06 5.5.2 for the 20" reference. Answer 2: We recently installed a system with a similar constraint. The customer didn't have the floor space for the robots restricted space + 20" so we had to install a "hard guard" to protect anyone on the outside of the fence.Technically it was not safe because there was still not 20" to eliminate the crush hazard while teaching but we noted it in the risk assessment and had the customer sign a special waver.