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I have a few minutes until my test unit ends with a glorious death... Source: Conformity Magazine The majority of internal office use equipment is given the classification of pollution degree 2. This is characterized as an area in which only non-conductive pollution normally occurs. Occasionally a temporary conductivity caused by condensation can be expected. Unless outdoor equipment is designed with a filtering system that limits the pollutants to that of level 2, the pollution degree 3 classification is assumed. Pollution degree 3 denotes an internal environment that is subject to conductive pollution or to dry, nonconductive pollution that could become conductive due to condensation. The increased likelihood of conductive debris bridging the insulation gap translates into a requirement for increased clearance and creepage distances. Source: DIN VDE 0110 part 1, page 4 Only non-conductive pollution occurs. Occasional temporary conducting as a result of condensation. Most Important Sources: IEC 60664, Insulation Coordination for Equipment within Low-Voltage Systems; and IEC 60529, degrees of Protection Provided by Enclosures "IP XY" X - protection against ingress of solid objects Y - protection against ingress of water IMO, the first "characteristic numeral" should be at least "5", because this is the the lowest level indicated by 60529 that dust penetration quantity will not "impair safety". BUT, in a hostile enviroment, "6" would probably be required to maintain PD2. Also, this would allow conformance to 60950-1, clause 2.10.7 for application of PD1 for all enviroments; and where the distances for Table 2L "go away". luck, Brian (if you do not have 60529, look at www. ubersuhner.com/mozilla/products/hs-p-rf/hs-p-rf-info/hs-p-rf-info-ip and www.lighting4sport.com/iprating.htm -----Original Message----- From: EMC-PSTC [ mailto:[email protected]] Sent: Friday, May 28, 2004 7:18 AM To: [email protected] Subject: Pollution degrees EN60950 Hi. Here's an easy one for Friday. What is the current interpretation on "Pollution Degree 2" when compared to the IP** table. I'm struggling with a borderline case and need to end my week happy ! Eric ------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to [email protected] Instructions for use of the list server: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html 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://www.ieeecommunities.org/emc-pstc
