http://www.ieee-pses.org/symposium http://www.emc2004.org/
Eric & Neil, TC108 is working on IEC 60950-22, ITE Installed Outdoors, which may hopefully put some parameters on a topic that is at present somewhat subjective. The standard is currently in its 2nd committee draft. In the meantime, you may want to review UL's Guideline for ITE installed outdoors at http://www.ul.com/ite/OutdoorITEGuideline.PDF, which, as I understand it, discusses much of the rationale that will be seen in the -22 standard, including installation category, transient protection, etc., in addition to pollution degree. Specifically, page 19 of this document discusses PD in relation to ingress protection - although it does not give a specific set of rules correlating IP rating to PD. In general, if you can show that an enclosure prevents the interior from being subject to conductive pollution, or to dry non-conductive pollution that could become conductive during periods of expected condensation, then the evaluator can assume PD2. In my estimation, this means that a minimum IP rating of IP54 would be required to safely assume PD2 on the interior of an enclosure intended for outdoor use - if the enclosure may likely be subject to hose-down, such as mounted on the side of a residence, then IP55 would be a minimum rating - in this particular case, where the homeowner may use a pressure washer, IP56 is more appropriate. If the unit is to mounted near to the ground, or below ground level, then IP57 is appropriate. As of today, this is a subjective call - I'm not sure how much detail will be given on this topic in the -22 standard - but I would hazard to guess that any effort to establish a firm set of rules for a broad spectrum of products will result in criteria that does not allow much room to easily apply sound engineering judgment - when you try to make a set of rules that covers everything, the rules tend to be very strict. A related topic that I would like to see resolved is the US national deviation that requires manufacturers of outdoor ITE to comply with UL50 environmental protection criteria for the US and Canada, and does not allow a cross-reference to IP ratings - this dual criteria typically doubles the cost of enclosure testing for manufacturers of outdoor ITE, with little objective justification. Doug Massey, NCE From: owner-emc-p...@listserv.ieee.org [mailto:owner-emc-p...@listserv.ieee.org] On Behalf Of Barker, Neil Sent: Monday, June 07, 2004 5:20 AM To: 'intert...@safety.demon.co.uk'; emc-p...@majordomo.ieee.org Subject: RE: Pollution Degrees EN60950 - are others struggling too ! http://www.ieee-pses.org/symposium http://www.emc2004.org/ Eric, I don't believe that you can correlate IP rating and Pollution Degree. While Ingress Protection can provide some assurance of a specific pollution degree, it can be perfectly acceptable for equipment with an IP rating of only say IP20 to be assesses for Pollution Degree 2 if the typical usage and the operating instructions indicate that it is suitable for use only in specific environments such as offices. You cannot test for a specific pollution degree, it is simply a condition that must be considered when performing a safety assessment. By the way, an outdoor enclosure can meet pollution degree 2. We manufacture products that are intended to be mounted on the outside of buildings or vehicles. The enclosure has an environmental seal and is vented through a dessicant breather, so the interior remains clean and dry. Best regards, Neil R. Barker C.Eng. MIEE MIEEE MSEE Manager Compliance Engineering e2v technologies ltd 106 Waterhouse Lane Chelmsford Essex CM1 2QU UK Tel: +44 (0)1245 453616 Fax: +44 (0)1245 453410 e-mail: neil.bar...@e2vtechnologies.com Web: http://www.e2vtechnologies.com From: intert...@safety.demon.co.uk [mailto:intert...@safety.demon.co.uk] Sent: 01 June 2004 19:51 To: emc-p...@majordomo.ieee.org Subject: Pollution Degrees EN60950 - are others struggling too ! http://www.ieee-pses.org/symposium http://www.emc2004.org/ Only two replies to this one last week - thank you guys - good supportive information. Can I entice any further responses ? I have IT equipment certified to EN60950 - Pollution Degree 2. The designer swears blind that his out-door cabinet can meet the requirements of Pollution Degree 2 - IT IS VERY DOUBTFUL. Do any environmental test labs in the UK test to EN60950 - Pollution Degree 2 ? I believe they only test IP ratings - that is why I need to correlate Pollution Degree 2 to an IP rating. While we are at it : Would anyone venture to correlate Pollution Degree 1 & 3 to IP ratings ? Eric ericm...@intertest.co.uk IEng, IIE, SEE, IIRSM INTERTest Systems UK the trading name of the test laboratory of E M Consulting Ltd Safety - Consultancy, evaluation and Int Certification 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 emc-p...@ieee.org 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: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com 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://www.ieeecommunities.org/emc-pstc 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 emc-p...@ieee.org 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: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com 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://www.ieeecommunities.org/emc-pstc
