[PSES] UL 61010-1 7.4 stabilty

[Doug Powell]

An interesting requirement came up today on a system that uses wheels for mobility. The inspector says clause 7.4 requires "... the unit be stable in the upright orientation, with wheels augmented with floor-braces or other such parts as necessary such that each wheel or brace can withstand four times the weight normally applied to it and the unit will remain stable and upright if any wheel or support is removed or broken." This is the exact wording in the letter report. I have no problem with stability requirements but I checked the third edition of UL 61010-1 and the national differences. I found nothing like this statement in the standard.  It didn't even mention the words wheels or castors. I am familiar with the four times requirements for handles, lifting rings and the like but not for wheels in particular. Also, I do know about various topple tests and the like are performed but a broken wheel or broken support test?   This made me wonder if the certifying agency has internal requirements or possibly the inspector is confusing wheel requirements from IEC 60601-1 for "transportable equipment" .   Does anyone know where the above may have originated?  Thanks everyone! Doug -- Douglas E Powell doug...@gmail.com https://www.linkedin.com/in/dougp01  Currently out of the office and working from my Android phone - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com>