Hello All: Just a quick followup on our discussion about the short circuit tests:
I just received my copy of Issue 3 of GR-1089, and when I went to replace Issue 2 I found a 1-page bulletin from Telcordia, dated December 1999, tucked in the front of my Issue 2 binder. The bulletin specifically addresses the "permissible response" of equipment to the short circuit test. Following is the text from that bulletin: "It is the Telcordia Technologies interpretation that when the short-circuit is applied to a circuit pack the operation of a fuse, circuit breaker, semiconductor fuse (e.g., diode, transistor, FET), and/or other current-limiting means (e.g., fold-back) without a fire, electrical safety, or fragmentation hazard is permissible. Further, it is the Telcordia interpretation that a sacrificial element such as a fuse, diode(s), transistor(s), semiconductor, or polymer over-current device(s) may fail as part of this test. The circuit pack is not required to be operational following this test. However, compliance shall be demonstrated by application of cheesecloth as specified in GR-1089-CORE, Section 4.5.2." I think the above statement clears up most, but not all, of the uncertainty regarding permissible failure modes under Issue 2. Of course, now we have Issue 3 with language that is not identical to this earlier statement. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.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: [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://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
