ELV has only one level of protection between hazardous voltages and the user. SELV requires two. See UL 60950 for further explanation.
Hard to tell what the connector has to do with it. Ask for the conditions of acceptability from the power supply report.
You may be able to salvage the supply. Try ground referencing the ELV (the + side). Then retest the power supply to assure the output remains within SELV limits under fault conditions (in particular, the basic insulation within the supply). You might gain approval for the application in your Class I equipment.
Bob Johnson Dave Wilson wrote:
We've been looking at a PSU which has UL recognition. Our -48V DC CO equipment has been assessed with respect to being powered from SELV source and this is stated in our UL report, but now that I've received a copy of the UL report for the PSU, it states that the output is ELV, not SELV, because of the connector interfacing the modules to the rack. The obvious answer is that we can't use it, but what is the practical reason for not being able to use ELV, given that they're both limited to below 60V DC and that our equipment is Class I earthed. Thanks! Dave Wilson Alidian Networks Inc. tel: (408) 273 4787 fax: (408) 273 4800 www.alidian.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: 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,"
