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More Answers From Erik Johnson
Innovation Manager at WireCrafters LLC
- Email: ejohnson [at] wirecrafters [dot] com
- Tel: (502) 357-7264
We have a robot that is enclosed by a wire fence enclosure 8 ft. in height that has a 32" wide access opening covered by a 36" wide interlocked sliding door. When the door is in the closed position the left hand side of the door is restrained by the upper track at the top, and by a channel shaped guide at the bottom. The right hand side of the door when closed is likewise restrained by the upper track, and is captured at mid frame within a channel shaped latch mechanism and at the door frame bottom by a channel shaped slam plate. This hardware is secured in place by tamper proof fasteners and captures and brackets the door within the channel shapes and will prevent the door from being pulled outward so as to potentially permit an individual to pass behind the door and to enter the cell. Will this door arrangement comply with R15.06 Clause 11.2.1 (e)?
Be advised that ANSI/RIA R15.06-1999 been revised by ANSI/RIA R15.06-2012. Reference ISO 14120 "Safety of machinery - Guards - General requirements for the design and construction of fixed and movable guards", Second edition 2015-11-01 5.3.12 Movable guards, which states that attachments shall only be removable with the use of a tool. Specifically, in regards to your question, yes, I believe that communicated design effectively "complies" with the ANSI/RIA R15.06-1999. Other standards in regards to interlocked guards: ANSI B11.19-2010 "Performance Criteria for Safeguarding", ISO 14119 Second edition 2013-10-01 Safety of machinery - Interlocking devices associated with guards - Principles for design and selection", and RIA TR R15.406-2014.
I design automation cells and regularly have conveyor openings in fencing. I've read through the RIA safeguarding manual but can't seem to figure out the proper distance I need to have hazards from the fence/tunnel end. The best I've come up with is treating a hole in the fence bigger than 4.7" as a reaching over scenario which doesn't quite seem correct.
ANSI/RIA R15.06-2012 126.96.36.199 "Minimum (safety) distances for guards" states that in relation to fixed and moveable guards, their minimum distance shall be determined according to the relevant requirements of ISO 13857. When preventing access with guards, ISO 13857 shall be used to determine the minimum safe distance. RIA TR R15.406-2014 Table 7 "Reaching THROUGH or AROUND a guard or protective structure" states "Openings within a guard >120mm (4.7 in.) are not permitted without additional safeguarding" ISO 13857 188.8.131.52 "Reaching through regular openings - Persons of 14 years of age and above" states "For openings > 120mm, safety distances in accordance with 4.2.2 shall be used. I agree that ISO 13857 4.2.2 "Reaching over protective structures" is not sensical in my opinion, to calculating minimum safe distance(s) based on an "e" dimension. I acknowledge that the aforementioned does not answer your question. Please feel free to email me directly firstname.lastname@example.org
If I'm not using any safety devices in my robot cell, what equation do I use for safety distance? I believe S = K*T + C is only for used with safety devices, due to the variables dealing with human interaction speeds. Is there a general equation for safety distance with regards to fencing and so maintenance personnel can't get pinned?
No, there is not a general equation in regards to safe distance with regards to "fencing". ISO 14120 (General requirements for the design and construction of fixed and movable guards) states that guards intended for preventing access to hazard zones shall be positioned to prevent parts of the body from reaching hazard zones according to ISO 13857 (Safety of machinery - Safety distances to prevent hazard zones being reached by upper and lower limbs) . For interlocked movable guards, safety distances according to ISO 13855 shall also be fulfilled. There are several factors that affect the safe distance of guards, to include but not limited to, protective structure opening dimensions, type of opening (i.e. slot, square, round), height of the protective structure, height of the hazard zone, etc.
Hello, In R15.06-2012, it states that there is a maximum height a barrier can be above adjacent walking areas is 7". This is to ensure that no one can come in contact with the equipment inside. In applications where there could be large build ups of combustible dust or require routine cleaning of the area, is there a different height/ acceptable alternative to the 7"? Currently there is an installation which the eentire robot system is shutdown in order to clean the area due to the height of the guarding. This dramatically hinders production and could potentially cause employees to attempt to defeat the guarding to maintain the equipment. Thank you for your help
To the best of my knowledge the maximum allowable distance from the bottom of the guard to the adjacent standing surface is 7". ANSI RIA R15.06-2012 Part 2 184.108.40.206 states "ISO 13857 shall be used to determine the appropriate dimensions for the opening from the bottom of the guard to adjacent standing surfaces and any openings in the guard" (also shown in figure 12) RIA TR R15.406-2014 states "... the opening between the walking surface and the guard shall be no greater than 180 mm (7 in.)." Note 2 states " In Canada, CSA Z432 and Z434 require a lower dimension of 150 mm (6 in.) .."
I have a robot cell with a large steel structure inside of it. The robot's workspace is inside of this structure. Access to one side of the structure is needed very rarely (maybe once a year) for maintenance on different parts of the structure. We have put "drop-n-lock" style fencing (requires a tool to lock and unlock the panels) with no movable panels (gates, etc..) on this side. Access to this area is only possible if fence panel(s) are removed. If maintenance/repair is needed, the operator will need to remove a panel (using a tool) to gain access. Is the fact that a tool is needed to do this sufficient? or do the panels that are deemed "removable" for maintenance need to be interlocked?
Good afternoon David, Fence panels that can only be removed by the use of a tool are referred to as Fixed Guards in ANSI B11.19-2019. Fixed guards do not require the use of an interlock. Movable guards, guards which can be opened without the use of tools, as defined by ANSI B11.19-2019. Thanks, Erik Johnson