Gary, and all, In my experience, the only sure way is to request the UL Report and read the Conditions of Acceptability very carefully, as well as the connector rating. I have seen connectors derated by UL and the company never changed their spec sheets or catalog (well, maybe now, after 7 years, they have changed them!). Also, some companies are sloppy with their specifications;-- not every connector or pin is rated for "current interruption" even while their page seems to imply that the whole series is so rated. Guess what, just a handful are rated for current interruption.
My best advise is, if you like what you see, call the manufacturer and pin them down. Then, when they tell you which parts are rated for current interruption, and you still like what you see, then you have them send you the UL report. Absolutely required, or you may be sorry. (You guys don't want to hear another story how I was almost sorry, but because of sheer luck managed to stumble on the fact that the connector that was being designed in was NOT rated for current interruption. I emerged a hero, but I was quacking in my sandals how close I came to blowing the whole thing!) Tania Grant [email protected] ----- Original Message ----- From: Gary McInturff Sent: Friday, June 22, 2001 3:59 PM To: '[email protected]'; [email protected] Subject: RE: Hot Swappable Power Supplies ? Richard, I'm a little less ebullient today than yesterday. Recognized Hot-swappable connectors exist but I sure can't find any way to quickly identify them. The UL classification is ECBT2. (Connectors for use in data, signal, and Power applications.) The UL guide information indicates that "unless otherwise specified in the individual recognitions, ...." the connectors have not been evaluated for current interruption. I began looking at both the UL on-line database and in an old recognition handbook, but no where could I find a reference to having been evaluated for current interruption. Of course I couldn't find any indication of the other things mentioned in the guide, such as conductor securing testing etc. So I decided to next check out some folks like Positronic who would likely have such a beast. Sure enough on their site for the Infinity series that it is "hot-pluggable (50 couplings per UL 1977 paragraph 15)" and they give a couple of contact sizes. (Earlier they give the UL and CSA file numbers) But here is the text from the UL data base Cat. No. IP followed by 18, 33, 48 or 56, followed by F or M, followed by any 4 digit alphanumeric code. No indication of meeting and of the "unless otherwise specified" items listed in the UL guide information for this category. Looks like there is no easy way to screen the connectors, you'll have to check with each vendor you are considering. Rats, so much for being a list-server information super hero - Ah well, tis the weekend and somebody has to go out and keep beer out of the hands of children so I'm off to the pub to destroy as much of it as I can.. Gary -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Thursday, June 21, 2001 9:30 AM To: [email protected] Subject: RE: Hot Swappable Power Supplies ? Gary, is the hot swappable approval included in the UL Conditions of Acceptability or is a different component category? Richard Woods ---------- From: Gary McInturff [SMTP:[email protected]] Sent: Thursday, June 21, 2001 11:41 AM To: 'Lesmeister, Glenn'; [email protected] Subject: RE: Hot Swappable Power Supplies ? They have "hot swappable connectors" that have already been subjected to the test as part of the component recognition, but I don't remember the CCN number. -----Original Message----- From: Lesmeister, Glenn [mailto:[email protected]] Sent: Thursday, June 21, 2001 6:26 AM To: [email protected] Subject: RE: Hot Swappable Power Supplies ? Richard, What is the test plan for making and breaking under load? In general, power supplies take a little bit of time to start up, so making contact under load is not going to be an issue. UL has specified a 200 cycle disconnect test and all they are concerned with is condition of the contacts afterward. They do not specify how fast you have to plug the supply from the connector, so this could be a factor. Typically, they have a short signal pin that must be fully seated for the supply to operate. Once you start pulling the supply, the signal pin breaks first and shuts down the high current before those contacts break. The slower you pull, the less likely you will draw an arc. Or course, the fast you pull, the shorter duration the arc. Regards, Glenn Lesmeister Product Regulatory Compliance Compaq Computer Corp. Tel: 281-514-5163 20555 SH 249, MS60607 Fax: 281-514-8029 Houston, TX 77070-2698 Pgr: 713-786-4930 [email protected] "I am empowered to do what makes sense!" -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Thursday, June 21, 2001 6:35 AM To: [email protected] Subject: RE: Hot Swappable Power Supplies ? We are currently evaluating a system with hot swappable power supplies and PCBs and here is what we have found needs to be checked: o Earthing pin makes first and breaks last o Primary and secondary power connectors are rated for make/break application o Access to hazardous voltages and energy hazards o Capacity of paralleled outputs may exceed energy hazard limits (we are adding PTCs on the backplane for each PCB which are also hot swappable) Richard Woods ---------- From: Richardson, William G [SMTP:[email protected]] Sent: Wednesday, June 20, 2001 5:50 PM To: 'Dan Teninty' Cc: '[email protected]' Subject: RE: Hot Swappable Power Supplies ? There must be a bleeder resistor (across the X caps) to make the AC input pins safe to touch once the supply is removed from the cabinet. If there are exposed voltage or energy hazards with the supply removed, there must be a restriction such that only trained personnel are instructed to do this OR a tool must be used to remove the supply. -----Original Message----- From: Dan Teninty [mailto:[email protected]] Sent: Wednesday, June 20, 2001 4:16 PM To: Emc-Pstc@Majordomo. Ieee. Org Subject: Hot Swappable Power Supplies ? Do any of my esteemed colleagues know of any specific requirements in 60950 (UL/CSA or EN) relating specifically to hot swappable power supplies? A search in the PDF version of UL/CSA 60950 reveals nothing specific when searching for "hot", "swap", or "power supply". A visual search of the TOC also reveals nothing specific. 2.6.5.4 deals with : Parts that can be removed by an operator Protective earthing connections shall make earlier and break later than the supply connections in each of the following: - the connector of a part that can be removed by an OPERATOR; - a plug on a power supply cord; - an appliance coupler. Compliance is checked by inspection. This is the most I could find that was related, and then it is referring to the AC side. Thought I would triple check with the collective brain trust to be sure. Appreciate any pointers to passages that I missed. Thanks, Daniel E. Teninty, P.E. Managing Partner DTEC Associates LLC Streamlining the Compliance Process 5406 S. Glendora Drive Spokane, WA 99223 (509) 443-0215 (509) 443-0181 fax ------------------------------------------- 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: Michael Garretson: [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.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: Michael Garretson: [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.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: Michael Garretson: [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.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: Michael Garretson: [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.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: Michael Garretson: [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.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: Michael Garretson: [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.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: Michael Garretson: [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.rcic.com/ click on "Virtual Conference Hall,"
