Art, On 3 Oct 1996, Art Michael wrote:
> 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. Obviously I can't speak for UL and wouldn't presume to discuss their policies. But I'm not surprised to hear that an experienced engineer is willing to exercise engineering judgment, on a case by case basis. That is exactly what all agency engineers do. > 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) I stand corrected! Humble apologies to all for the incorrect information. Perhaps I'd better stop writing these messages in the middle of the night, from dingy hotel rooms, when the brain gears are not fully engaged ... or (groan!), maybe dementia senilis is setting in. Mea culpa. :-( The way the standard reads right now, components listed in Annex P1 must comply with CSA, UL, or both standards; but components listed in Annex P2 only need comply with CSA or UL standards, not both. Interestingly enough, this covers a wide range of major components, including insulation materials, power supplies, transformers, EMI filters, motors, plastics, etc. So, according to Annex P2, quite clearly you can choose to use a UL recognized insulation system per UL 1446, or evaluate the materials per CSA 0. > 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). Yes, my reading of the standard concurs with Tiki and Norm. It would also be interesting to hear confirmation from some UL ITE specialists ... Are you out there Bob? > Within UL, to my knowledge and experience, other than for this > provision in UL 1950, 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). As I mentioned before, I assume that most agency engineers do have the latitude to exercise engineering judgment. This should be even easier now that a precedent appears to have been set. Seeing that both CSA and UL seem to have agreed that CSA 0 and UL 1446 are equivalent and acceptable alternatives, there appears to be no reason why UL evaluations can't be performed using CSA 0, in lieu of UL 1446. :-) BTW, it seems to me that if a manufacturer is paying a safety agency good money for consulting services, the client has the right to specify exactly which services are desired and which standards should be used. As safety experts, the agencies should be expected to RECOMMEND the best path, of course, and also explain why they perceive this to be the best path. But, ultimately, the informed decision should belong to the client. > ThanX for your input. I look forward to continuing this > emailversation (a non-standard word coined by me. :-) I like it! And who knows? Maybe one day we can skip the virtual chats and actually talk in real-time ... :-) > 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. Yes, these are interesting times. Will even get more interesting as we all inevitably harmonize with world wide standards... Best regards, Egon Disclaimer: The above are all personal opinions that do not necessarily reflect the position of my employer. I am neither authorized, nor presume, to be a spokesman or to set policy for my employer.
