EN 600065 for audio and video equipment judges that the creepage between traces on a coated PCB is non existent.....
As you may see, many standards do not have the same opinion about the subject. Regards, Gert Gremmen, (Ing) ce-test, qualified testing =============================================== Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ =============================================== >>-----Original Message----- >>From: [email protected] >>[mailto:[email protected]]On Behalf Of [email protected] >>Sent: Friday, February 01, 2002 6:41 PM >>To: [email protected] >>Cc: [email protected] >>Subject: RE: Pollution Degree vs. Creapage Distance >> >> >> >>Thanks for the response and yes I was referring to EN60950. My >>apologies for not stating that in my message. >> >>I guess I was thinking that solder mask might be considered >>"enclosed" . Obviously the solder mask would not qualify as >>hermetically sealed or an approved insulating compound. Just >>trying to understand the Pollution degree 1 criteria. Am I to >>understand that only approved coatings constitutes "enclosed"? >> >>Thanks >> >> >>Rick >> >>-----Original Message----- >>From: Ron Pickard [mailto:[email protected]] >>Sent: Friday, February 01, 2002 9:22 AM >>To: Rick Busche >>Cc: [email protected] >>Subject: Re: Pollution Degree vs. Creapage Distance >> >> >> >>Hi Rick, >> >>I am assuming (ugh) that you are referring to EN60950 2nd >>Edition. If so, clause 2.9.6 clearly >>addresses your question by requiring hermetic sealing or such >>enclosing to prevent the ingress of >>dirt and/or moisture. IMHO, solder mask does not and cannot >>provide this type of protection and, >>therefore, cannot be used as such. >> >>And, as for your question, "Why are the secondary circuit spacing >>requirements based on a primary >>input voltage?". Look into Annex ZB of the above standard and >>then to the reference clause 6.2.1.2. >>Your answer is there as it relates to TNV circuits. >> >>Again, this is assuming that you were referring to the above standard. >> >>I hope this helps. >> >>Best regards, >> >>Ron Pickard >>[email protected] >> >> >> >> >> >> >> [email protected] >> >> Sent by: To: >>[email protected] >> owner-emc-pstc@majordom cc: >> >> o.ieee.org Subject: >>Pollution Degree vs. Creapage Distance >> >> >> >> >> 01/31/02 01:01 PM >> >> Please respond to >> >> rbusche >> >> >> >> >> >> >> >> >> >> >> >>I am wading through the creapage and clearance requirements for >>secondary circuits using the values >>in tables 5 and 6. It becomes very apparent that the creapage >>distances become quite large when you >>assume material group IIIb (CTI). For operational insulation, >>this might be 2-3X the clearance >>values. My question to the group is: >> >>Does the application of a solder mask allow for a change from >>pollution degree 2 to pollution degree >>1? I understand that conformal coating requires significant >>testing when used to reduce spacings >>per table 7, but in this case I am only asking if solder mask can >>be used to improve the pollution >>concern. >> >>Assuming this is NOT the case, are there any other practical >>suggestions? Cutting slots in >>multilayer cards is a bit tricky. I can live with 0.7mm of >>clearance, but 2.5 mm (operational) or >>5.0 (reinforced) of creapage is a bit difficult on a densely >>populated power supply. >> >>One last question. Why are the secondary circuit spacing >>requirements based on a primary input >>voltage? >> >>Thanks >> >>Rick Busche >>E&S >>[email protected] >> >>------------------------------------------- >>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: >> Michael Garretson: [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: >> No longer online until our new server is brought online and >>the old messages are imported into >>the new server. >> >> >> >> >> >>------------------------------------------- >>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: >> Michael Garretson: [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: >> No longer online until our new server is brought online and >>the old messages are imported into the new server. >> >>
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