RE: UL legal requirement
Jeff, Check the scope of UL1950/CSA950, 3rd edition harmonized standard and you will find that a minimum voltage is not specified, just a maximum of 600 V. Note that the standard is applicable to equipment connected to the mains Therefore, your battery-operated camera and toys are O.K., but not O.K. if there is a power cord connecting them to building mains power. Then the appropriate standards apply. Tania Grant, tgr...@lucent.com Lucent Technologies, Communications Applications Group -- From: Rich Nute [SMTP:ri...@sdd.hp.com] Sent: Friday, September 17, 1999 3:04 PM To: jbai...@sstech.on.ca Cc: emc-p...@ieee.org Subject: Re: UL legal requirement Hi Jeff: > I am trying to find a basic document from UL and or CSA regarding the legal > requirement of > UL or CSA listing. I am thinking along the same lines as the European LVD. > Can anyone > offer insight as to whether this documentation exists? UL and CSA are private organizations. To my knowledge, neither has published any document describing how their respective certifications are required by Federal, State, County, and City laws. I believe that both feel that such a publication would be out of place and rather presumptive. How the various laws invoke third-party certification has been rather completely discussed in this forum from August 16 to August 19. See: http://www.rcic.com/ Click on: Virtual Conference Hall Click on: Browse Recent EMC-PSTC Threads Click on: Next 25 until you get to August 19. Then, click on: U.S. National Product Safety "Laws" (18) > The real question is: Is there a legal requirement to obtain UL or CSA > listing on a product > that operates at a low voltage (below 50VAC or 75VDC), does not have a > circuit that would > be classed as a TNV circuit, does not operate in hazardous explosive > environments, and > does not consume a high amount of power? The product is also not connected > to the mains > supply, it is specified to require power from a safety listed supply. The answer to this question must be determined from the NEC and from OSHA regulations. The NEC has regulations for low-voltage wiring installations (Article 625). So, if the product involves low-voltage building wiring, then it must be certified by UL or other acceptable certification. Since stand-alone (i.e., not a part of the building installation) low-voltage products are not addressed, then the NEC does not apply to such products. Consequently, under the NEC, flashlights and similar battery- operated products are not required to be certified. Furthermore, low-voltage products provided with an external power supply (adapter) need not be certified since the product is not part of the building installation. I was unable to find anything under OSHA rules that implies exemption of low-voltage products. Best regards, Rich - Richard Nute Product Safety Engineer Hewlett-Packard Company Product Regulations Group AiO Division Tel : +1 858 655 3329 16399 West Bernardo Drive FAX : +1 858 655 4979 San Diego, California 92127 e-mail: ri...@sdd.hp.com - - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
1999 paper posted
Hi All, I decided to post my 1999 IEEE EMC Symposium paper on magnetic field probes, "Signal and Noise Measurement Techniques Using Magnetic Field Probes," as well as the current probe paper. The 1999 paper provides background for last month's Technical Tidbit on the paperclip probe. The 1999 paper is a bit long (~600K) because of more graphic content. It is much shorter that the nearly 2 Megabyte file on the CD-ROM that was given out at the Symposium even though it has much better resolution Both papers can be found under "Technical Goodies for Download" near the top of my index page at: http://emcesd.com Happy reading! Doug -- --- ___ _ Doug Smith \ / ) P.O. Box 1457 = Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o |Email: d...@dsmith.org \ _ /]\ _ / Website: http://www.dsmith.org --- - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Site up and paper posted
Hi All, Well the servers at SiteAmerica are working again and my site is up ( http://emcesd.com ) I have uploaded my 1998 IEEE EMC Symposium paper "Current Probes, More Useful Than You Think." It has lots of background information to support this month's Technical Tidbit article on measuring voltages with current probes. There is also information on making "differential common mode" current measurements. The technique uses relative phase information between two matched current probes to diagnose EMC problems using a spectrum analyzer. The method of reading relative phase information from the spectrum analyzer display and interpreting the result are discussed in detail. Look under "goodies for download" or there is also a link from the current probe article this month. Doug -- --- ___ _ Doug Smith \ / ) P.O. Box 1457 = Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o |Email: d...@dsmith.org \ _ /]\ _ / Website: http://www.dsmith.org --- - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
hp 141T's
Group: A comment on the old hp 141T series of spectrum analyzers, that someone (probably someone like me) recently suggested: We have some and I like them, BUT: a) They are no longer supported by hp and some of the parts are no longer even available. b) If you are going to get one, you'd better be willing to spend a lot of time getting very familiar with the manual and learning how to repair and align it yourself. It will be hard to find someone that is competent to work on it. c) Treat it carefully. Old equipment can last a long time, or it can break down tomorrow, depending on how it was used or abused before you got it. With these, it is specially easy to blow the mixer or the front end. A lot of the "idiot proofing" safeguards that are built into modern computerized equipment, (and that we now take for granted) do not exist in the old stuff. d) Know who you are dealing with. Old equipment like this comes with either NO WARRANTY or 30 days at most. You could easily end up with an expensive door stop. Try explaining that to your boss after bragging about how much money you just saved! e) If you are outside the US, forget about it. You will have a hard time getting it into your country. There is no "CE" mark on this equipment, and never will be. f) If I were working for the government or for a big company, I wouldn't get one of these at all. It would be too hard to justify it to the many layers of non technical people that get involved, specially later, when you have to spend twice what it cost to get it fixed. Sometimes this actually makes sense with old sequipment, but you'll never be able to explain that to the bean counters! :) I would only get one if I worked for a small company with an understanding boss that had a lot of money and a real love of equipment. Also a sense of humor. Regards, Lou - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
