Rick, I can't speak for any of the Euro-Norms, but in aerospace an internally-toothed ring terminal is generally considered adequate. That said, I believe that a toothed washer will provide the function that the customer wants, but it's hard to tell. Are they concerned about some sort of really harsh (salt spray, acid, etc.) environment? If so, then some sort of sealer should be applied to each joint after assembly.
As always, these are my views only and they're probably wrong! Steve Chin StreamLogic Corp. Menlo Park, CA, USA sc...@streamlogic.com Rick Busche (rbus...@es.com) wrote: >I have a projector assembly which is essentially a large metal >structure (frame) with a metal projector platform which swivels for >purposes of maintenance. The structure is painted steel, with pressed >in bronze bushings at all motion points each of which have been >measured at significantly less than 0.10 ohms. Arguably, there is no >guarantee that these structures will remain bonded at these levels >over time and bonding wires (braid, with crimped ring lugs) have been >added across the pivot points. These wires are secured to the >structure using a toothed washer and screw. The intent of the toothed >washer is to bight through the paint to ensure conductivity. >My customer's safety officer (in Europe) is now insisting that the >paint must be ground off to bare metal and coated with Zinc paint >prior to affixing the lug to the structure. I am concerned that this >is an excessive requirement. It has been my understanding that the >toothed washer (and the screw for that matter) creates a gas tight >connection which is acceptable for all bonding requirements. >I would be interested in hearing from the group regarding this bonding >issue. I can find no standard or specification which disallows this >biting washer or requires Zinc paint. >Any comments would be appreciated. >Rick Busche >rbus...@es.com > > > >
