Hi, It is true that 4.4.4 allows a mechanical or electrical enclosure not serving as a fire enclosure to be HB when it is located externally to a fire enclosure.
Phones and video games could be HB for this reason, however they could also have been tested as being a limited power source under 4.4.5.2 thus not requiring a fire enclosure. This approach is often seen for keyboards, mice and sometimes laptops. John Fee -----Original Message----- From: Art Michael [mailto:amich...@connix.com] Sent: 20 January 2000 21:01 To: Andrews, Kurt Cc: Colgan, Chris; emc-p...@ieee.org Subject: RE: Open Letter re ITE Flammability (Source is NAFM) To Kurt: I believe it is possible to utilized an internal "enclosure" to protect against fire (and other hazards) and then, the outer case (the subject of the NAFM letter) does not need to meet the V-1 requirement. I know, for a fact, that this technique was utilized in other product lines (phones & video games, for instance) so that the outer case did not serve as the "enclosure" and could be made of less expensive polymers. And, to Chris: It has long been recognized on this side of the Atlantic, that TVs and other home electronics devices benefit from the use of flame-resistant "enclosures" (you can interpret that as: flame-resistant enclosures reduce the fire-risks associated with such products). That is why UL 6500 varies from 60065 and why flame-resistance of one of the cornerstones of the myriad of ANSI/UL standards. It's good to learn that 60065 is adding finally adding flammability requirements for enclosures. Regards, Art Michael Int'l Product Safety News A.E. Michael, Editor 166 Congdon St. East P.O. Box 1561 Middletown CT 06457 U.S.A. Phone : (860) 344-1651 Fax : (860) 346-9066 Email : i...@connix.com Website: http://www.safetylink.com ISSN : 1040-7529 ---------------------------------------------------------------------- On Thu, 20 Jan 2000, Andrews, Kurt wrote: > > According to 4.4.4 of both UL 1950 and EN 60950 monitors should be at least > V-1. 4.4.4 says that fire enclosures of less than 18 kg (about 40 lb.) have > to be at least V-1. For fire enclosures over 18 kg it needs to be 5V. So if > a monitor has a UL mark it should be at least V-1. A monitor case should > definitely be a fire enclosure as 4.4.5.1 says the following items need a > fire enclosure and I'm sure that all monitors have at least some of these: > components having unenclosed arcing parts, such as open switch and relay > contacts, and commutators; components having windings, such as transformers, > solenoids and relays; wiring; semiconductor devices, such as transistors, > diodes and integrated circuits; resistors, capacitors and inductors. > > > Kurt Andrews > Compliance Engineer > Tracewell Systems, Inc. > 567 Enterprise Dr. > Westerville, OH 43081 > Ph. 614-846-6175 > Fax 614-846-7791 > Email: kandr...@tracewell.com > > -----Original Message----- > From: Colgan, Chris [SMTP:chris.col...@tagmclarenaudio.com] > Sent: Thursday, January 20, 2000 12:40 PM > To: emc-p...@ieee.org > Subject: RE: Open Letter re ITE Flammability (Source is NAFM) > > > Interesting and worrying. Does EN60950 call up flammability > requirements > for polymeric enclosures? If not, I guess I had better look for a > PC with a > NRTL mark as well as a CE mark - and then check it is V-0 rated. > > You may be amazed to know that while UL6500 (safety of audio visual > products) calls up flammability requirements for all product > enclosures, the > current edition EN60065 only requires the back and ventilated parts > of > television receiver enclosures to made of "slow burning material or > better a > fire retardant material". There is no requirement for other > products such > as amplifiers, CD players etc. The next edition of EN60065 > addresses the > problems of enclosure flammability but there must an awful lot of > highly > flammable hi-fi equipment out there. Think twice before placing > that > yuletide candle on top of your hi-fi stack. > > Regards > > Chris Colgan > EMC & Safety > TAG McLaren Audio Ltd > > mailto:chris.col...@tagmclarenaudio.com > > > > -----Original Message----- > > From: Art Michael [SMTP:amich...@connix.com] > > Sent: 20 January 2000 14:48 > > To: emc-p...@ieee.org > > Subject: Open Letter re ITE Flammability (Source is NAFM) > > > > > > Hello all, > > > > Recently my attention was drawn to an open letter from the > National > > Association of Fire Marshals, detailing their concerns with 94-HB > > enclosures, which - according to tests they initiated - can be > readily > > ignited by external sources. > > > > A quote from their letter: "In November and December of 1999, SP > (the > > Swedish National Research and Testing Institute) tested five > computer > > monitors - all of which had been or are available to consumers. > Three of > > the five were made with fire-resistant plastic housings. Repeated > > attempts to ignite these monitors failed. Two of the five monitors > were > > made with HB rated plastic housings. A SINGLE MATCH IGNITED EACH > OF THESE > > QUICKLY." > > > > [The emphasis in the last sentence is mine] > > > > The NAFM letter can be viewed at: > <www.firemarshals.org/openletter.html> > > > > My interests were piqued and the subject-matter served as the > basis for an > > article in the current issue of Int'l Product Safety News. To > further > > this discussion, I ask you to read the open letter and then ask > yourself; > > > > A) What is your company's business practice ? Do they, 1: Just > meet the > > requirements (per a given standard) ? or, 2: Strive to provide > > equipment that is "safe" beyond the requirements of the standards > ? > > > > B) Should ITE (and other) product safety standards be concerned > with > > external sources of ignition. > > > > C) Do you agree that ITE should be singled out for scrutiny, given > that > > children's bedrooms (the impetus behind this open-letter), and in > fact, > > whole households, are replete with easily ignited materials. > > > > Regards, Art Michael > > > > Int'l Product Safety News > > A.E. Michael, Editor > > 166 Congdon St. East > > P.O. Box 1561 > > Middletown CT 06457 U.S.A. > > > > Phone : (860) 344-1651 > > Fax : (860) 346-9066 > > Email : i...@connix.com > > Website: http://www.safetylink.com > > ISSN : 1040-7529 > > > > > > > > > > --------- > > 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). > > > ===================================================== > Authorised on 01/20/00 at 17:38:33; code 37f48bf367698790. > > > > ********************************************************************** > The contents of this E-mail are confidential and for the exclusive > use of the intended recipient. > If you receive this E-mail in error, please delete it from your > system immediately and notify us either by E-mail, telephone or fax. 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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). --------- 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).
