If the unit conforms to clause 2.5, then it will be specifically noted in the CB test report and the safety agency's conditions of acceptibility.
The CB report for the end-use equipment will indicate if the power supply shall be rated as a limited source. If an LPS is required, power supplies with 'similar' ratings are not interchangeable if the test report does not indicate conformity to clause 2.5 of IEC/EN/UL60950-1. There is no requiremnent in IEC/UL/EN 60950-1, to provide a 'LPS' mark. Use on a non-LPS rated unit may limit allowable materials used for external connections. From: [email protected] [mailto:[email protected]]On Behalf Of Pickard, Ron Sent: Wednesday, January 21, 2009 10:59 AM To: Christine Rodham Cc: [email protected] Subject: RE: Safety Experts: Limited Voltage Pwr Supplies vs. Non-Limited Voltage Power Supplies Hi Christine, It's always a joy experiencing part substitutions, eh? And, LPS actually refers to a Limited Power Source as defined in the IEC60950-1 series. Anyway, have you had a chance to review the other power supply's applicable safety report(s)? Whether it is or is not LPS will be determined (and your comfort level) during that review. That missing LPS marking could simply be an oversight on the part of that manufacturer or it's not a LPS. The fact is that you really won't know until you look at the reports, and I hope that that manufacturer will make the safety report(s) available to you. Also I believe that the LPS marking is an accepted industry practice, not a regulatory requirement. If anyone disagrees with this, please provide a compelling argument. IHTH. Best regards, Ron Pickard [email protected] From: [email protected] [mailto:[email protected]] On Behalf Of Christine Rodham Sent: Wednesday, January 21, 2009 12:39 PM To: [email protected] Subject: Safety Experts: Limited Voltage Pwr Supplies vs. Non-Limited Voltage Power Supplies Hi List Members, We have a vendor that provides us a unit that uses an external power supply ( 90- 240VAC) The power supply is labeled LPS after the model number which means: Limited Voltage Power Supply. They recently changed vendors to another power supply with the EXACT same rating Except it was not marked as a LIMITED voltage power supply. Our supplier says this is not a compliance / safety issue because both supplies are recognized by UL and have the same voltage and current rating. So the $64,0000 dollar question is can you use a non- LPS in place of a LPS if they have the same rating? Thanks in advance, Thank you in advance! Christine Rodham - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
