Re: [PSES] Krypton Photoionisation Detector Lamps
Thanks to everyone who responded. I've learned a lot. Below is an email I got from one of the manufacturers of a Krypton PID lamp which explains things nicely. I understand that UV in this band known as VUV or Vacuum Ultraviolet is quickly absorbed in air so unless you are very close to the window there is no hazardous UV present. Since the window in the PID requires frequent cleaning we will interlock the enclosure to power down the lamp during that operation. The other areas of concerns mentioned by many of you we will also keep in mind and deal with. Thanks again for your help. The Other Brian -- Dear Brian, first of all I would like to know, whether you are intending to use a DC or a RF PID lamp, since general safety precautions are a bit different. Secondly we always recommend not to look directly into UV sources, although regarding the UV-output of Krypton PID lamps there are little safety concerns. The overall UV-intensity emitted by a PID lamp is very low. The bulb consists of a glass that actually blocks the VUV-lines used for the ionization process. So, the light emitted through the bulb is mainly in the visible and not harmful. The window consists of MgF2 and is actually transmitting deep UV light. However, the VUV-lines of Krypton between 117 - 180 nm are absorbed in air within a few millimeters. So, in instrument designs there are usually no UV hazards to be considered. Little gaps and holes don't cause a problem. However, you should take care in the instrument design that no UV degradable materials like polymers are in the proximity ( 5 mm) of the MgF2 window, since they may suffer under UV irradiation. The emitted UV intensity can be measured by appropriate calibrated UV meters. However, these devices are rather expensive, so it is the cheaper option to enclose the UV lamp into a housing that no UV light can escape. If you have any further questions please don't hesitate to contact me. Best regards, -- -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Oglesbee, Robert A Sent: Tuesday, August 06, 2013 1:59 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] Krypton Photoionisation Detector Lamps Depending on the lamp and setup they also produce enough ozone that you need to use them in a well-ventilated space... Rob Oglesbee (765) 494-5234 Senior Instrumentation Specialist Jonathan Amy Facility for Chemical Instrumentation -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Tuesday, August 06, 2013 11:53 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Krypton Photoionisation Detector Lamps In message 64D32EE8B9CBDD44963ACB076A5F6ABB0265F7F9@Mailbox-Tech.lecotech.local, dated Tue, 6 Aug 2013, Kunde, Brian brian_ku...@lecotc.com writes: We are looking at using a Krypton Photoionisation Detector Lamp with one of our products. It produces short wavelength Ultraviolet light used to ionize molecules. These low power lamps produce 10eV at 123.0nm and 10.6eV at 116.9nm. That's at the hot end of the UV-C band. It will make your teeth fluoresce. My question is regarding safety. I have found many many documents and data sheets on the internet but none mention any safety precautions or concerns with their use. Are the UV levels so low and/or at a wavelength that they pose no hazards to human skin or to the eye? No, not at all. There is a serious safety issue. Wikipedia is your friend: http://en.wikipedia.org/wiki/Ultraviolet You have to scroll down to 'Harmful effects'. No doubt the regulatory requirements are different in different countries. - 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 LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - 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
Re: [PSES] Mains cord EN 50525
John, Thanks for your advice. Will read the suggested standards for further info. Regards, Scott On 7/8/13 1:10 AM, John Woodgate j...@jmwa.demon.co.uk wrote: In message ce274439.1bdf8%scott...@gmail.com, dated Wed, 7 Aug 2013, Scott Xe scott...@gmail.com writes: Have all mains cords for Europe including UK to comply with EN 50525 now? BS 6500 is superseded by this new EN 50525? Are there any major differences from the outer surface? It's not quite like that. Cables in CENELEC were covered by 'Harmonized Documents' (HD), which was supposed to be a temporary status until EN standards could be written. The issue may have been forced by the Commission trying to reserve the term 'harmonized standard' for those that it notifies in the Official Journal. So EN 50525 (which isn't all that new and is a multi-part standard) just replaces the parts of an HD. You probably need to look at EN 50525-11 or EN 50525-12. - 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] Krypton Photoionisation Detector Lamps
In message 64D32EE8B9CBDD44963ACB076A5F6ABB0265FA43@Mailbox-Tech.lecotech.local, dated Wed, 7 Aug 2013, Kunde, Brian brian_ku...@lecotc.com writes: I understand that UV in this band known as VUV or Vacuum Ultraviolet is quickly absorbed in air so unless you are very close to the window there is no hazardous UV present. In fact, the band designations for UV-C (100 nm to 280 nm) and VUV (10 nm to 200 nm) overlap. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Why is the stapler always empty just when you want it? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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
[PSES] Grandfathered requirements for ETSI
Hi, My company makes 2.4 GHz proprietary wireless products for European use (not WiFi, BT or ZB). These units are qualified under EN 300 328. We understand that EN 300328 v1.8.1 will become law the 1st of 2015. We've been selling wireless products for many years in the EU and the installed base is in the 10s of thousands of units. However, the changes dictated by v1.8.1 will break our radio protocol and destroy the compatibility between new units (that must be v1.8.1 compliant) and those already installed in the field. This is a huge issue for us and any other vendor that may have the misfortune of having a large installed base of pre-existing products. Is there any provision in ETSI rules that allows for backwards compatibility with preexisting products? I have a hard time believing that they wouldn't have made some sort of provision for this. Any help or advice would be greatly appreciated. Mark Mark Tucker Director of Hardware Engineering RFM 3079 Premiere Parkway, Suite 140 Duluth GA 30097 mtuc...@murata.com - Forwarded by Mark Tucker/US/MuRata on 08/07/2013 12:57 PM - From: IEEE LISTSERV Server (16.0) lists...@ieee.org To: Mark Tucker mtuc...@murata.com, Date: 08/07/2013 12:56 PM Subject:Welcome to the emc-pstc email list [Last updated on: 18-Oct-2011] *** * * * The IEEE PSES EMC-PSTC E-Mail Forum * * * *** 18 Oct 2011 Welcome to the EMC-PSTC E-Mail Forum! ** To send a message to the EMC-PSTC Forum, simply send an e-mail message to the following address: emc-p...@ieee.org All mail sent to this Internet address will be re-sent to about 900+ worldwide subscribers to the EMC-PSTC list by an automated list server (Listserv). Listserver posting may take up to 8 hours. Please set your mailer to ASCII text. ASCII text is readable by all mailers, while other mail formats are not. Do not attach files. ** To SUBSCRIBE to the EMC-PSTC mailing list, send an email message to lists...@ieee.org and place the command: SUB EMC-PSTC full_name in the body of the message. ** HOW TO UNSUBSCRIBE The only way to UNSUBSCRIBE, or remove your name, from a list is to send an email message to lists...@ieee.org and place the command SIGNOFF EMC-PSTC in the body of the message. Do not append a signature file. ** HOW TO SET LISTSERV OPTIONS The listserv understands many commands and has many options. For a complete list of options send the command INFO REFCARD to lists...@ieee.org and a complete list of commands will be emailed back to you. The most commonly used commands are listed below. As with all commands to the listserv, send an email message to lists...@listserv.ieee.org and include the commands in the body of your message, one command per line. ** Old messages will be Archived at (aprox. Feb. 2003): http://www.ieeecommunities.org/emc-pstc ** Should you have any questions, send them to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com ** Subscribe or Unsubscribe issues should addressed to: Scott Douglas emcp...@radiusnorth.net Mike Cantwellmcantw...@ieee.org . ** ** * Charter and Guidelines * ** ** 05 September 2001 This Forum is operated by the IEEE Product Safety Engineering Society. The Forum was founded to discuss product safety issues. But, we also discuss product EMC and other product regulatory issues. We discuss world-wide standards and regulations. We discuss technical issues related to interpretation and measurement. And, we discuss safety and EMC issues not currently published in standards and regulations. This Forum is a tool to help us do our jobs by sharing information. MESSAGE CONTENT GUIDELINES -- 1. Postings and responses should be limited to information or queries relating to Product Safety, EMC, or Regulatory Compliance topics. 2. Posted information should not be confidential or in any way proprietary. 3. Please don't use the EMC-PSTC for private correspondence. Private correspondence should be addressed directly, unless it has broad appeal or interest. 4. Please put your name at the end of any message you send (some e-mail
Re: [PSES] Grandfathered requirements for ETSI
In message ofbdbfd6e6.3fbff34c-on85257bc0.005d28a2-85257bc0.005d8...@murata.com, dated Wed, 7 Aug 2013, Mark Tucker mtuc...@murata.com writes: We've been selling wireless products for many years in the EU and the installed base is in the 10s of thousands of units. However, the changes dictated by v1.8.1 will break our radio protocol and destroy the compatibility between new units (that must be v1.8.1 compliant) and those already installed in the field. This is a huge issue for us and any other vendor that may have the misfortune of having a large installed base of pre-existing products. Is there any provision in ETSI rules that allows for backwards compatibility with preexisting products? I have a hard time believing that they wouldn't have made some sort of provision for this. I don't know the details of this development, and I'm afraid I don't have time to research it, but there is a general principle, which may be very cold comfort for you. If you don't bother to watch what happens to standards that affect your products, others will make decisions that you may find adversely affects your products, even if that was not intended (as would normally be the case; standards committees try to behave responsibly, but are not infallible). By 'watch', I mean participate in the standards work, at least at the trade association level, and preferably at the national standards committee level if possible. So contact your national standards committee IMMEDIATELY and ask for leave to present your case (if you are certain of it) to the committee. If possible, copy your application and explanation of your concerns to the Secretary of the relevant ETSI committee, whose contact details you should be able to find on the ETSI web site (but it is a bit of a maze). -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Why is the stapler always empty just when you want it? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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] Grandfathered requirements for ETSI
Hello, In general, no. The standards change to keep up with changes in interference level, spectrum planning, problems seen, etc. As I think John Woodgate already said.. You can sit on the standards committee and influence it. I used to be on the group for writing EN 300 328 and EN 301 893 (I am not anymore, I should add! V1.8.1 was not me! J ) and the group was mostly made up of manufacturers protecting the interests of their companies, and regulators protecting their spectrum. Can I ask exactly what the problem is? Is it the Medium Access Protocol issue? Are you concerned that your device may choose to change channel mid-operation, or something? Actually, I'm guessing that (spectrum sharing) cannot be the issue because that aspect of V1.8.1 became mandatory on 23rd October 2012. Is it the new power measurements? I'm curious because maybe there is a solution, after all. If that fails, I have the ETSI group chairman's e-mail address, if you want it. J Michael. Michael Derby Regulatory Engineer ACB Europe From: Mark Tucker [mailto:mtuc...@murata.com] Sent: 07 August 2013 18:01 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Grandfathered requirements for ETSI Hi, My company makes 2.4 GHz proprietary wireless products for European use (not WiFi, BT or ZB). These units are qualified under EN 300 328. We understand that EN 300328 v1.8.1 will become law the 1st of 2015. We've been selling wireless products for many years in the EU and the installed base is in the 10s of thousands of units. However, the changes dictated by v1.8.1 will break our radio protocol and destroy the compatibility between new units (that must be v1.8.1 compliant) and those already installed in the field. This is a huge issue for us and any other vendor that may have the misfortune of having a large installed base of pre-existing products. Is there any provision in ETSI rules that allows for backwards compatibility with preexisting products? I have a hard time believing that they wouldn't have made some sort of provision for this. Any help or advice would be greatly appreciated. Mark Mark Tucker Director of Hardware Engineering RFM 3079 Premiere Parkway, Suite 140 Duluth GA 30097 mtuc...@murata.com - Forwarded by Mark Tucker/US/MuRata on 08/07/2013 12:57 PM - From:IEEE LISTSERV Server (16.0) lists...@ieee.org To:Mark Tucker mtuc...@murata.com, Date:08/07/2013 12:56 PM Subject:Welcome to the emc-pstc email list _ [Last updated on: 18-Oct-2011] *** * * * The IEEE PSES EMC-PSTC E-Mail Forum * * * *** 18 Oct 2011 Welcome to the EMC-PSTC E-Mail Forum! ** To send a message to the EMC-PSTC Forum, simply send an e-mail message to the following address: emc-p...@ieee.org All mail sent to this Internet address will be re-sent to about 900+ worldwide subscribers to the EMC-PSTC list by an automated list server (Listserv). Listserver posting may take up to 8 hours. Please set your mailer to ASCII text. ASCII text is readable by all mailers, while other mail formats are not. Do not attach files. ** To SUBSCRIBE to the EMC-PSTC mailing list, send an email message to lists...@ieee.org and place the command: SUB EMC-PSTC full_name in the body of the message. ** HOW TO UNSUBSCRIBE The only way to UNSUBSCRIBE, or remove your name, from a list is to send an email message to lists...@ieee.org and place the command SIGNOFF EMC-PSTC in the body of the message. Do not append a signature file. ** HOW TO SET LISTSERV OPTIONS The listserv understands many commands and has many options. For a complete list of options send the command INFO REFCARD to lists...@ieee.org and a complete list of commands will be emailed back to you. The most commonly used commands are listed below. As with all commands to the listserv, send an email message to lists...@listserv.ieee.org and include the commands in the body of your message, one command per line. ** Old messages will be Archived at (aprox. Feb. 2003): http://www.ieeecommunities.org/emc-pstc http://www.ieeecommunities.org/emc-pstc ** Should you have any questions, send them to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com ** Subscribe or Unsubscribe issues should addressed to: Scott Douglas emcp...@radiusnorth.net Mike Cantwellmcantw...@ieee.org . ** *
Re: [PSES] breakage of the fuse
What is the breaking capacity of the fuse? Sounds like it may be a low breaking capacity fuse. If it is you should change it to a high breaking capacity fuse. From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Boštjan Glavic Sent: Tuesday, August 06, 2013 12:46 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: breakage of the fuse Dear safety experts, 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? Best regards, Bostjan SIQ - 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: 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] 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
Re: [PSES] breakage of the fuse
When a fuse's interrupting (breaking) capacity is too low for an application and the fuse opening interrupts current in a manner that causes the glass to crack or break, the temperature gradient across the glass and the internal pressure created by the plasma when the fusible element vaporized can and will push some of the vaporized metal out of the confines of the glass and contaminate the surrounding area. Sometimes the deposited metal is not readily visible and even if visible does not always clean up easily or well. The Creepage Distances may be compromised. Depending on the overall design, this can cause increases in touch current (leakage current) and otherwise increase the risk of electric shock with continued product use. Replacement of the fuse can become more frequently necessary due to the contamination allowing unintentional current flow to keep the product operating. If each successive fuse replacement uses the same fuse, more of the same may result. If the product isn't returned for replacement or discarded, the fuse might eventually be replaced with a larger rated fuse with possible further degradation of safety. 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
[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.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] 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
