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Field Service Kit and Equipotential Bonding
There is a 133 page handbook for implementing ANSI/ESD S20.02; it is ESD TR20.20. Here’s what it says about equipotential grounding and field service kits. Included in section 5.1.3:
“When neither AC equipment or auxiliary grounds are available, an equipotential bonding system may need to be used. In this situation, all of the items in the system are bonded together so that the charge that resides on the elements will be shared equally and therefore there will be no potential difference between the items. Once this step has been completed it is safe to handle ESD sensitive parts without inducing damage. A real life example of this is often observed in office equipment field service operations. For safety reasons the service technician will often disconnect the AC power cord which detaches the equipment from ground. In order to safely install ESD sensitive products into the equipment, it is necessary to electrically connect or bond together the service technician, the equipment frame and the ESD sensitive product. Once bonded together an ESD event will NOT occur when the technician handles the product or installs it in the office equipment.”
Can anyone wear their wrist strap on their leg instead of their wrist?
Does it matter where a person should wear the wrist strap?
Desco is happy to share our knowledge of ESD control through our Answer’s Database. We have 5 NARTE Certified ESD Technicians, we are a member of the ESD Association, and we have 30+ years of manufacturing products for ESD control. See the following question submitted through our questions box and subsequent answer.
Answer:
It does say around the wrist in the ESD Handbook ESD TR20.20 section 5.3.2.3.1 “Use, For maximum effectiveness, wrist straps should be used properly following these guidelines. 1. The wrist strap cuff should fit snugly and make full skin contact around the wrist.”
Here’s more information: “All personnel shall be bonded or electrically connected to the grounding / equipotential bonding system when handling ESDS [ESD sensitive] items.” [ANSI/ESDS20.20-2007 section 8.1] “When personnel are seated at ESD protective workstations, they shall be connected to the grounding / equipotential bonding system via a wrist strap system.” [ANSI/ESDS20.20-2007 section 8.2] “The wrist strap system should be tested daily to ensure proper electrical value.” [ANSI/ESD S1.1 Annex A, 3. Frequency of Functional Testing] If the wrist strap reliably passed the wrist strap tester or continuous monitor with the wristband around a person’s ankle or other body contact, it is acceptable.
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