Brian, You wrote: > I have recent experience where a CPS with a 60601 > report, and tested for patient contact, was installed in ITE. The > box could no longer pass all safety requirements for a C.O. device.
'C.O. device' -- 'Central Office'? Does this means the medical power supply was subjected to Bellcore/Verizon-style telecomm system tests? Pat Lawler EMC Engineer SL Power Electronics Corp. "Brian O'Connell" <[email protected]> wrote on 09/15/2010 08:56:52 AM: > My employer designs and manufactures, among other things, component > power supplies for medical, IT, instrument, industrial, and other weird stuff. > > Unlike other safety-critical components such as X/Y caps, VDRs, > switches, connectors, etc; there are no 'accepted' safety standards > for component power supplies. No need to tell me about IEC61204, > UL1310, UL1012, IEC61558, etc; as these are 'boutique' standards. > Each major product safety standard has some specific requirements > for power sources - of which most requirements overlap. Other than > an indicated conformity to Articles 600 or 725 of NEC, it is very > unusual to be able to drop in a component power supply from > different sources even when the ratings are identical. > > Until there is an industry-standard component power supply product > safety standard that has been harmonized by all national codes, and > is cited in the Big Four (60950/60065/60335/60601), there will be no > drop-in replacements without re-test with an alternate construction > amendment to your CB report. > > Final note - I have recent experience where a CPS with a 60601 > report, and tested for patient contact, was installed in ITE. The > box could no longer pass all safety requirements for a C.O. device. > This has been discussed in previous PSES threads - a medical power > supply is not necessarily 'safe' in a consumer or ITE box. > > Brian > > -----Original Message----- > > From: [email protected] [mailto:[email protected]]On Behalf Of Amund > > Westin > > Sent: Wednesday, September 15, 2010 12:19 AM > > To: [email protected] > > Subject: SV: [PSES] IEC 60950-1 vs IEC 60601-1 > > > > The end product is an ITE (DVB) and in the previous models, > > we have made use > > of an open frame AC/DC power supply unit. This PSU had CB certificate > > according to IEC60950-1. Then we went to a third party body > > for testing the > > complete unit according to IEC60950-1. Since we had a CB > > certificate, the > > scope of work for testing the ITE was limited a lot, since > > no testing / > > examination on the PSU itself was necessary. > > > > Now, we want to change PSU to another open frame AC/DC power > > supply unit. > > This PSU has a CB cert acc to IEC 60601-1, while the end > > product still shall > > conform according to IEC60950-1. > > > > Since the new PSU shall be placed inside the ITE, some > > safety test and > > evaluations must be done. > > But we would also assume that a 601-1 PSU should be more > > "safe" than an > > 950-1 PSU, seen from an application point of view. > > > > We accept that some safety testing must be done on the end > > product. But we > > find it a bit strange if the introduction of this medical > > PSU involves more > > testing than if we had made use of a 950-1 PSU. > > > > #Amund > > > > > > -----Opprinnelig melding----- > > Fra: Brian O'Connell [mailto:[email protected]] > > Sendt: 14. september 2010 18:56 > > Til: [email protected] > > Emne: Re: [PSES] IEC 60950-1 vs IEC 60601-1 > > > > WARNING - Fractious dichotomous isochroous nondeterministic > > reply follows. > > > > I am not certain of Mr. Westin's use of "PSU". IEC60950-1 > > has no definition > > for the phrase 'power supply unit', and contextual meaning is not > > consistent. IEC60601-1 uses the phrase 'power supply unit' only when > > referring to a separate external power source. > > > > For a COMPONENT power supply, where the final determination > > is the end-use > > installation - the 'PSU' CB report can use a TRF based on > > almost any product > > safety standard that would scope a 'PSU'. > > > > For a power supply that has been assessed as an end-product, neither > > standard provides complete coverage for the requirements of > > the other for > > many uses, and for some uses either standard could provide > > coverage for a > > superset of the requirements. Anyone wanna see a De Morgan > > reduction of that > > logic ? > > > > The coming (????) of the UL/EN/IEC62368-1 standard may > > provide an unintended > > formal method to 'bridge' various requirements for component > > power supplies. > > > > Most I.T. CB reports for component power supplies require > > the repeat of some > > Type Tests in the end-use installation. So for a medical > > 'PSU', the pudding > > would not get cooked until it was subject to tests in your I.T. box. > > Conversely, the 3d edition of 60601-1 specifically addresses > > the use of I.T. > > component power supplies for some medical equipment. > > > > The CB report could be considered valid; or not. > > Additional tests could be required; or not. > > > > Non-related Note: the '#' at the signature threw some > > interesting errors for > > my auto-mail program - thanks for the programmatic work-out. > > > > Brian > > > > > -----Original Message----- > > > From: [email protected] [mailto:[email protected]]On > > Behalf Of Amund > > > Westin > > > Sent: Tuesday, September 14, 2010 1:05 AM > > > To: [email protected] > > > Subject: IEC 60950-1 vs IEC 60601-1 > > > > > > Is it possible to make use of a CB certificated (IEC > > > 60601-1) PSU, into a > > > ITE which shall be approved according to IEC60950-1? > > > > > > Well, I assume that's OK, but should we expect additional > > > tests on the PSU / > > > ITE since it's not CB acc to IEC60950-1? > > > > > > Thanks. > > > #Amund - ---------------------------------------------------------------- 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]>
