I have come up with a question and will try to strip it to its essentials. Consider a part which requires a fire enclosure, as a hypothetical example a primary rectifier bridge with reinforced insulation. It is safe to touch, with no live parts, so top openings or side access is not restricted. A bottom enclosure is provided out beyond the 5ยบ projection.
The question is what is the fire enclosure? Clause 4.6.1 places no limits on side or top openings since access is not an issue. In fact it appears the opening can extend from the bottom up the sides and over the top and down the other side to the bottom. Is it necessary for a fire enclosure to envelope the part? The next difficult question is what is a part placed in this opening? If parts are placed in the opening (anywhere beside or above the part requiring the fire enclosure), they must be V-1 (etc. see 4.7.3.2), but if outside the opening they may be HB (etc. see 4.7.3.3). No distance is specified, so in my case it appears a plastic window 12 inches away appears to be occupying an opening in an enclosure. I can apply 4.7.1 method 2, but do the enclosure requirements of method 1 fail to be usable in this situation? Any opinions? Robert Johnson ITE Safety ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
