Re: [PSES] breakage of the fuse
The standard 35A or so breakage capacity glass fuses may fulfill your needs in a household situation with relative low prospective short circuit currents. If used on branches with higher currents (say 64A or even more) the prospective short circuit current will be even higher (50 kA) leading to the failure you mentioned. Small glass fuses can be obtained with 1500 A safe breaking capacity. If you need even more you need other type (large in general) of fuses and fuse holder. Not that the wiring diameter in the protected circuit should keep up with that. Regards, Ing. Gert Gremmen, BSc g.grem...@cetest.nl www.cetest.nl Kiotoweg 363 3047 BG Rotterdam T 31(0)104152426 F 31(0)104154953 Before printing, think about the environment. -Oorspronkelijk bericht- Van: emc-p...@ieee.org [mailto:emc-p...@ieee.org] Namens Boštjan Glavic Verzonden: Thursday, August 08, 2013 6:21 AM Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: RE: [PSES] breakage of the fuse Dear all, Thank you for your comments. The below mentioned construction was rejected. The client needs to use high breaking fuse and not enhanced fuse. The problem is that in every switch mode power supply you can get high short circuit current which is causing non-high breaking fuse to burst (there is a resistance 1ohm even with power supply cord). This happens during fault condition testing in primary circuit right after the fuse (e.g. across the varistor or diode bridge). But test has to be performed on the correct branch circuit and in peak of input voltage. But the problem is that standard does not define precisely how to conduct the abnormal condition (e.g. IEC 60950-1). There are many power supplies on the market with low breaking or enhanced breaking type of fuse and they are approved by different certification bodies. Some power supplies have only TR5 low breaking fuse. That's why I decided to ask you experts for 2nd opinion. UL has a PAG about this issue and does not allow it. However in the past many such construction were acceptable also by UL. Best regards, Boštjan Glavič Head of Laboratory, Laboratory of Electronic Engineering www.siq.si SIQ Ljubljana, Trzaska c. 2, SI-1000 Ljubljana, Slovenia, VAT ID: SI23509678 t +386 (0)1 4778 265, m +386 (0)41 391 283, f +386 (0)1 4778 444 -Original Message- From: Pete Perkins [mailto:peperkin...@cs.com] Sent: Wednesday, August 07, 2013 11:33 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Cc: Boštjan Glavič Subject: RE: [PSES] breakage of the fuse Bostjan commented: During the abnormal tests in primary circuit, internal input fuse operates and glass breaks. However, fuse is inside the tubing and broken glass does not spread around. Would you accept such construction? - - - - - Bostjan, Such a question can have several answers, among other things it depends upon who the 'you' is. If the 'you' is a party who suffered personal injury or financial damage they probably wouldn't be willing to accept such construction you will hear from them. If the 'you' is a test house or regulator they probably would be looking closely for a way to not accept such construction. If the 'you' is a tinkerer who likes to solve difficult problems they probably would accept such construction be happy that they could fix it and get on with using the product. Perhaps the question you should ask is 'would your mother accept such construction?' or would she be all over you because of what happened. Would the general public know how to clear out the mess in the fuseholder and insert a new fuse to get back in operation? Think about it; not all questions have one simple answer. :) br, Pete Peter E Perkins, PE Principal Product Safety Engineer PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 fone/fax p.perk...@ieee.org - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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 emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list,
Re: [PSES] Standards Dates
Once you purchase the standard, all information about this current edition is included in the front matter including effect effective dates. That is, dates when it becomes mandatory. Thanks -doug From: Scott DouglasSent: Wednesday, August 7, 2013 10:09 PMTo: EMC-PSTC@LISTSERV.IEEE.ORGReply To: Scott DouglasSubject: [PSES] Standards DatesFor Harmonized standards in the EU, you can get a list of the standards, their various versions, and which expires when.For UL or CSA standards, how does one tell or determine when a particular version of a standard is no longer usable to show compliance?Example - I have legacy product approved to UL 60065, 7th Edition but the approval was in 2004 or 2005. Then I have new products approved in 2012. I have seen various ways of listing the standard in different reports.Typical is this: UL 60065:2003 R04.04 or UL 60065:2003 R11.06I have tried to get a straight answer from UL but so far not much help.Can anyone explain, does UL have expiration dates on standards or a point where they are n o longer usable? I know they send out letters about changes and updates and such, but those never seem to help much and often come at the cost of a file review.Likewise for CSA. Take CAN/CSA-C22.2 NO. 60065-03 (R2012). Just on their web site and see they show it as: CAN/CSA-C22.2 NO. 60065A-03 (R2012) - Amendment 1:2006 to CAN/CSA-C22.2 NO. 60065-03.But I don't find anyway to know when my legacy products to older versions of the standards need to be submitted for update.Kevlar on - I suppose you will tell me I need to review each change and determine it's impact on my product to see if it needs submitted to the agency again. I try to do that, but when you inherit dozens and dozens of legacy products all at once, it can be daunting at the least.I'm just hoping someone can put a simple explanation to this or that there is an easier way.All input appreciated and thank you.Scott-This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgAll emc-pstc postings are archived and searchable on the web at:http://www.ieee-pses.org/emc-pstc.htmlAttachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc.Website: http://www.ieee-pses.org/Instructions: http://listserv.ieee.org/request/user-guide.htmlList rules: http://www.ieee-pses.org/listrules.htmlFor help, send mail to the list administrators:Scott Douglas emcp...@radiusnorth.netMike Cantwell mcantw...@ieee.orgFor policy questions, send mail to:Jim Bacher: j.bac...@ieee.orgDavid Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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 emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com
Re: [PSES] Standards Dates
UL will also post the information for some of the more common standards on their web site, including UL 60950-1http://www.ul.com/global/eng/pages/offerings/industries/hightech/informationtechnology/dates/609501b/ and UL 60065http://www.ul.com/global/eng/pages/offerings/industries/hightech/consumerelectronics/standards/. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.commailto:ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. From: Doug Powell [mailto:doug...@gmail.com] Sent: Thursday, August 8, 2013 7:50 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: Standards Dates Once you purchase the standard, all information about this current edition is included in the front matter including effect effective dates. That is, dates when it becomes mandatory. Thanks -doug From: Scott Douglas Sent: Wednesday, August 7, 2013 10:09 PM To: EMC-PSTC@LISTSERV.IEEE.ORGmailto:EMC-PSTC@LISTSERV.IEEE.ORG Reply To: Scott Douglas Subject: [PSES] Standards Dates For Harmonized standards in the EU, you can get a list of the standards, their various versions, and which expires when. For UL or CSA standards, how does one tell or determine when a particular version of a standard is no longer usable to show compliance? Example - I have legacy product approved to UL 60065, 7th Edition but the approval was in 2004 or 2005. Then I have new products approved in 2012. I have seen various ways of listing the standard in different reports. Typical is this: UL 60065:2003 R04.04 or UL 60065:2003 R11.06 I have tried to get a straight answer from UL but so far not much help. Can anyone explain, does UL have expiration dates on standards or a point where they are n o longer usable? I know they send out letters about changes and updates and such, but those never seem to help much and often come at the cost of a file review. Likewise for CSA. Take CAN/CSA-C22.2 NO. 60065-03 (R2012). Just on their web site and see they show it as: CAN/CSA-C22.2 NO. 60065A-03 (R2012) - Amendment 1:2006 to CAN/CSA-C22.2 NO. 60065-03. But I don't find anyway to know when my legacy products to older versions of the standards need to be submitted for update. Kevlar on - I suppose you will tell me I need to review each change and determine it's impact on my product to see if it needs submitted to the agency again. I try to do that, but when you inherit dozens and dozens of legacy products all at once, it can be daunting at the least. I'm just hoping someone can put a simple explanation to this or that there is an easier way. All input appreciated and thank you. Scott - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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 emcp...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald: dhe...@gmail.commailto:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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 emcp...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald dhe...@gmail.commailto:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at:
Re: [PSES] breakage of the fuse
-Original Message- From: Boštjan Glavič [mailto:bostjan.gla...@siq.si] Sent: Wednesday, August 07, 2013 21:41 Peter, Fuse is not replaceable. It needs to be sleeved (tubed) and only manufacturer can repair the power supply. Due to the tubing, there is not likely that vaporized metal would affect other parts and decrease safety distances. Boštjan - Don't be too hasty in that tubing assessment, simply because it's there. The pressures involved can be substantial and the sealing ability of the tubing would need to be carefully reviewed, as well as application methodology (work instructions and craftsmanship). After a fuse opens the circuit involved, the tubing needs to be cut open to look for evidence of metal vapor deposition. Assume nothing. During my employ at a well known NRTL, I was responsible for testing glass tube and other fuses, as well as having seen glass tube fuses crack, ferrules become dislodged (even on solder in place fuses), when the interrupting (breaking) capacity was too low for an application in end-product equipment. I'm glad the fuse will be replaced with another, more approriate type. Peter Tarver This email message is for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. If you are not an intended recipient, you may not review, use, copy, disclose or distribute this message. If you received this message in error, please contact the sender by reply email and destroy all copies of the original message. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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 emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
