One of my customer mentioned that grounding requirement for mobile carts have been changed. Only ESD wheel are allowed and no more using grounding chain. Is that true? In fact i did not come across any update on the mobile carts grounding requirement. Thanks
ESD wheels will surely provide a better contact with ground than a chain, however theres no requirement how you achieve it. Either chain, ESD wheels or both resistance of mobile cart with ground should be less than 10^9 ohms.
Thanks a lot for the clarification. I do agreed that ESD wheel provide better contact compare to drag chain. It performed better with loads while drag chain performence does not change with loads. Thanks again
There are no new requirements proposed to say that wheels are required. As with most things, if you make the measurement and I meets the requirements, you are compliant. It does not matter how that is accomplished.