Doug, Since you have LPS and a fire enclosure is not required, your foam is not within a fire enclosure and so the requirement does not apply. If test house wants to be picky, then they could say that it now must meet the decorative parts criteria which means you must provide an HBF foam.
Regards At 12:37 29/09/2000 -0400, Massey, Doug C. wrote: > >Hello All - > >I desperately need some opinions on an interpretation of a particular clause >in UL1950. The background: I have an investigation underway to UL1950 of a >portable handheld computer, powered by battery and other power options, all >of which meet the requirements for inherently LPS. > >Clause 4.4.3.1 states, "Components inside a FIRE ENCLOSURE........", and >continues into flammability requirements of materials and components. > >Clause 4.4.5.2 addresses components not requiring a fire enclosure, and >states, "....-components in a SECONDARY CIRCUIT supplied by a limited power >source complying with 2.11, provided that...." > >The product in question absolutely meets the requirements of clause 4.4.5.2, >which I interpret to mean that a fire enclosure is not required. However, >the test house performing the evaluation is applying all of the criteria of >clause 4.4.3.2. Unfortunately, I have a relatively small foam spacer inside >that does not meet the flammability class HF-2 or better as specified in >4.4.3.2. > >The test house tells me that yes, the product meets the requirements for the >exemption allowed in 4.4.5.2, but that I cannot literally interpret the >statement in 4.4.3.1 to mean that the substance of clause 4.4.3 regards only >component and material flammability ratings inside a fire enclosure. > >I guess I'm a literal type guy - I can't see any other way to interpret the >standard. Can anyone shed some light on this interpretation so that I can >read between the lines and understand the real requirements? I'm not trying >to make an enclosure of gasoline-impregnated paper, and with the exception >of a small (but critical) piece of foam, everything else meets the >requirements without the exclusion allowed by 4.4.5.2. > >HELP !?!? > > >Doug Massey >Safety Approvals Engineer >LXE, Inc. >Norcross, GA., USA >Ph. (770) 447-4224 x3607 >FAX (770) 447-6928 >e-mail: masse...@lxe.com > >Cruise our website at: http:\\www.lxe.com > > > >------------------------------------------- >This message is from the IEEE EMC Society Product Safety >Technical Committee emc-pstc discussion list. > >To cancel your subscription, send mail to: > majord...@ieee.org >with the single line: > unsubscribe emc-pstc > >For help, send mail to the list administrators: > Jim Bacher: jim_bac...@mail.monarch.com > Michael Garretson: pstc_ad...@garretson.org > >For policy questions, send mail to: > Richard Nute: ri...@ieee.org > > Peter Merguerian Managing Director Product Testing Division I.T.L. (Product Testing) Ltd. Hacharoshet 26, POB 211 Or Yehuda 60251, Israel Tel: 972-3-5339022 Fax: 972-3-5339019 e-mail: pmerguer...@itl.co.il website: http://www.itl.co.il TO LEARN ABOUT AUSTRALIAN AND NEW ZEALAND REQUIREMENTS, CONTACT ME AT THE EARLIEST STAGES OF YOUR DESIGN; REQUIREMENTS CAN BE TRICKY! ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
