Hi John,
You wrote: >We use screws which have combined hex/posidriv heads with >serrations under the head, which eliminates the need for star washers. >We find these work very well for zinc plated parts. On epoxy painted >parts, they also seem to cut thru the paint and give a satisfactory >result - you might feel "happier" if you have more than one screw >for any given part. Using these screw types may be "satisfactory" at the time of production, but what will be expected when the product is placed into service and into varying environments? Will the newly exposed chassis surfaces (I agree that they would very small) become so oxidized that the oxidation leaches to the "satisfactory" ground connection? Probably not, but IMHO, due diligence might prescribe an evaluation. >We also use self-clinching PEM nuts with good results. >Typically we find that where a grounding conductor has been >brought to a particular area of our products, we would still >pass the 0.1 ohm, 25A test when we remove the conductor. May I ask how you pass this test when, as you stated, the conductor is removed (just curious). Please provide clarification. Best regards, Ron Pickard rpick...@hypercom.com ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
