In our production environment, we use the retractable grounding reels and attach them to the top of the cabinets under test. I have taken over as the site ESD Coordinator and noticed that some employees have been attaching to the UUT and not to the workbench using the argument that they are at the same potential due to the chassis being grounding. However, if the employee were to attach to a portion of the chassis that is isolated, they would be in violation and not even know and put product at risk.
With the retractable grounding units, they have a clip of course. Would it be permitted to attach the wrist strap to that clip? Are any of you aware of a retractable ceiling mounted grounding system that allows direct connection of an ESD wrist strap?
I don’t think there is anything specifically wrong with attaching to the retractable grounding reel per ANSI/ESD S20.20 as long as you can verify the requirements are met (grounding, product qualification, compliance verification). As I don’t have any experience using a retractable grounding reel in a factory I can’t speak of any risks associated with it like the ground connection being lost, but if there is a risk of this, it may not be the best option.
I am not aware of any specific retractable ceiling mounted grounding system. Perhaps you could adapt an existing retractable grounding reel to mount on the ceiling if that option seems to fit best in your production line. Thanks