Hello Egon, My comments follow your responses.
-------------------------------------------------------------------------- On 30 Sep 1996, Egon H. Varju wrote: > The way most safety agencies look at this is that if all the materials used > meet or exceed Class B requirements, then the transformer is Class B. I agree (with the exception of UL who normally requires compliance with UL 1446 when a "system" of materials. The point of this thread is that I've apparently located a situation in which UL will accept a "non-system" of materials for coils operating above Class A (105 Deg/C) conditions. I believe this to be a unique situation but it may show up in other harmonized standards that I am not familiar with. > BTW UL1950/CSA950 requires components to meet the requirements of UL _and_ CSA > (not _or_!). I refer you to Annex P.2 (pages 208 and 209) of the Third Edition (the Harmonized Standard); The second sentence reads, "In the U.S. and Canada, any of the following components which comply with EITHER the specified UL or CSA standards are considered to comply with the requirements of this standard." When one drops down to the item addressing Sub-clause 2.2.2 - Insulating materials, the ALTERNATIVE standards listed are, UL 1446 or CSA 22.2 No. 0. (the capitalized emphasis is mine) Note: I spoke with Tiki Wong in your Rexdale/Etobicoke office and he concurs with my position. Also, I spoke with Norm Hellriegel (the Insulation Systems' guru at UL's Melville office, and he agreed with my reading of the standard, but did offer the caveat that he was not extremely familiar with the harmonized ITE standard and its requirements (nor would I expect him to be). > But nowhere in the standard does it say that any or all components > must be UL and/or CSA certified. Any uncertified component may be used, as > long as it is tested and/or examined to ensure compliance with the applicable > standards. If you have a recognized insulation system, then this makes life > easier; otherwise, surely the agency engineer should be capable of examining > the materials used to ensure compliance. Within UL, to my knowledge and experience, other than for this provision in UL 1446, an engineer cannot determine the long-term degradation of a "system" of materials other than by having a UL 1446 Recognized Insulation System in place. I'm not aware of any relief in this requirement if the coil in question operates above Class A conditions (other than in this particular scenerio). > Just my personal opinion .... > > Egon Varju ThanX for your input. I look forward to continuing this emailversation (a non-standard word coined by me. :-) It would be interesting to learn what other UL or CSA "requirements" may no longer be required when harmonized standards replace individual U.S. or Canadian standards. Regards, Art Michael A.E. Michael, Dir. of Engineering Product Safety Int'l 166 Congdon St. East, Dept. EM Middletown CT 06457-8061 U.S.A. Phone : (860) 344-1651 Fax : (860) 346-9066 Email : [email protected] Website: http://www.safetylink.com
