Mobile Equipment Grounding

Technical Questions
#1

Hi All,
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

Regards
Andy

#2

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.

Regards,
George

#3

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

#4

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.