The main problem is that a power supply unit is clearly not a medical device in itself and it cannot realistically be assessed for patient leakage currents or indeed the strict requirements for the testing of the medical device that it connects to. However if there is 4kV rms withstand between mains and dc output (for 230V mains) or 3kV (for 120V mains) and the ac leakage current at the dc output pins is less than the limit for the patient and if the dc output pins are not accessible, and it complies with IEC 60950-1, and it is unlikely to be touched by the patient then it will be suitable for use with a medical device that does not have electrical contact to a patient.
Not all the above requirements may be applicable to a particular medical device, and if a power supply does not meet all the above it will have to be assessed along with the device to verify full compliance of with IEC60601-1 (Medical electrical equipment). Andy Clifford Conformance Ltd - Product safety, approvals and CE-marking consultants The Old Methodist Chapel, Great Hucklow, Buxton, SK17 8RG England Tel. +44 1298 873800, Fax. +44 1298 873801, www.conformance.co.uk Registered in England, Company No. 3478646 ________________________________ From: Carl Newton [mailto:emcl...@gmail.com] Sent: 02 November 2009 20:20 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Medical Grade Brick Power Supplies not Listed? Dear List Members, I'm new to medical safety compliance and I've been told that medical grade external (brick) ac/dc converters can only be R/C and not Listed. I've done some brief searches in the UL database and elsewhere and that does appear to be the case at a glance. Would one of you with experience with this issue please confirm or deny? It's my understanding that the two issues for medical grade are low leakage current and high electric strength. I don't understand why the medical grade brick can't be Listed. Thanks in advance, Carl - 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 <emc-p...@ieee.org> 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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - 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 <emc-p...@ieee.org> 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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com>
