David, Your question isn't so "stupid" as you say.
It is correct that the "primary" grounding screw (the first screw connected to the ground wire from the AC inlet) shouldn't be used for any purpose other than grounding. However, the standards do allow that screws and fasteners can be used to pass this grounding on to other parts of the chassis. In that context (I guess you could call them "secondary" ground screws), your question is valid. It is worthwhile considering labeling these screws with a ground label; especially if a user could remove this screw and still operate the product. I guess what I'm trying to say is: your specific question may have an obvious answer; but the fact that you were thinking about how to make the product safe is just as important as quoting any standard chapter and verse. It is never stupid to use logic and reason along with the standards. Chris Maxwell | Design Engineer - Optical Division email [email protected] | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | "A friend is a person who knows the song in your heart because they stopped singing their own song long enough to hear yours :-) > -----Original Message----- > From: David Sproul [SMTP:[email protected]] > Sent: Monday, September 16, 2002 5:46 PM > To: Doug McKean > Cc: EMC-PSTC > Subject: RE: Earthing through screws. > > > Hello Doug, > I believe you are right. If I had taken the trouble to read EN60950 para > 2.6.5.7, I would have saved my self from asking stupid questions. > > Thanks also to all those who responded to my orignial posting. > > regards, > David Sproul. > > > ------------------------------------------- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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"
