Doug, This sounds completely new to me. I thought that the various national electric codes regulated building wiring and such. I have never thought of them as an equipment design authority.
Most of the electric codes simply recommend using "approved" equipment; then the approval (and hence internal fuse sizes) are left up to the agency that does the "approving", such as UL, CSA, etc. The agency, or lab then uses a product standard as a guideline for testing the specific product. Most of us in the forum work designing a specific product; so we only need to satisfy the product standards used by UL, CSA, etc. Perhaps your OEMs are in a different regulatory word as compared to most of us in the forum? Or, alternatively, are your OEMs confusing product safety with building wiring safety and applying a "circuit breaker" design rule to a "fuse"? Just curious. Chris Maxwell Design Engineer Nettest 315-266-5128 [email protected] From: [email protected] [mailto:[email protected]] On Behalf Of POWELL, DOUG Sent: Monday, December 15, 2003 11:30 AM To: John Woodgate; [email protected] Subject: RE: Fuse Ratings for thermal considerations John, The product standards I use do not reference the 125% limit. However, many of my OEMs who use this product must meet NEC provisions. This is apparently where the limit comes into play. In addition, the Canadian Electric code and the German nation code has similar provisions. -doug Douglas E. Powell Corporate Compliance Dept. Advanced Energy Industries, Inc. Fort Collins, CO 80525 USA This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
