I don't have the answer to Glenn's question, but do have a comment on Nick's response.
Nick states: "The rating of a UL rated fuse is more or less the current at which it blows. The rating of a fuse to IEC 127 (used throughout Europe) is more or less the working current of the fuse and the circuit it protects" This may or may not be true. Last I looked, UL Listed miniature fuses (typically 1 X 1-1/4in cartridge size) and branch circuit protection fuses are required to carry 110% of their rated current for a minimum specified time and 100% continuously; Listed microfuses are required to carry 100% of current continuously. For a UL Recognized fuse (including 5 X 20mm cartridge sizes, of which you most likely refer), this is not necessarily the case, though it may be. Thus, "the rating of a fuse ... is more or less the working current of the fuse" is as true for a UL Listed fuse as it is for an IEC 127 fuse. For Recognized Component fuses, any deviation from the base requirements for Listing is rationale to allow only Recognition. These base requirements include, but are not limited to: physical dimensions, current carrying capacity, "calibration" or time-to-open characteristics, time delay characteristics for time delay rated fuses, etc. In the US and Canada, general purpose branch circuits relying exclusively on safety certified branch circuit fuses (which IEC127 and other miniature and microfuses are not), respectively, can operate at 100% of the branch circuit rated current. Branch circuits protected exclusively by fuses have become the exception in the US and Canada, where circuit breakers dominate. One is left with the question: are fuses used throughout Europe as an integral part of mains circuit protection? By this I include the power supply cord as an extension of the mains, whether or not it is included by definition or is absolutely correct in everyone's perspective. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina Homologation Services peter.tar...@sanmina.com ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
