Most agencies allow conformal coat only if approved material and audited process, and only to mitigate spacings - not intended as MOP or MOPP. Perhaps a potting compound rated for DSR if across an iso boundary? In any case, coating material in med equip must meet IEC60950-1 requirements for c/c fill. To make a long story short - for using a coating as a MOPP you will need to write it up in your risk management file and conduct pagan rituals.
Polyurethane paint? Rated for its intended use in your product? Why do you need additional isolation/barriers from 24V source? Leakage? Brian -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of McInturff, Gary Sent: Tuesday, January 31, 2012 5:41 PM To: '[email protected]' Subject: coatings as an insulator I'm trying to solve a Class II - no earth ground connection - medical device problem. I have one complex part that I need to insulate such I can get two MOPP's of insulation value and it has to be done through an insulator - I can't use creepage or clearance distances to solve the problem. Has anyone used a coating as an insulating barrier? I don't see a condition that allows coatings per se., but on the other hand I see that they talk about insulations which form supplementary insulation with a working voltage of greater than 71V shall be..... and then goes on to explain that it must be multiple layers each capability of ,meeting the dielectric test requirements, but it leaves voltages lower than undescribed, and I'm at 24 Vdc. One part would be painted with a very durable Polane paint which is more a backed on plastic than a true paint. If part A is painted it mates via internal threads of the shaft and provides an insulation bearer on the surface between each part - breaking the conductive path. It also has a dielectric withstand test value of about 2.5 kV, and for two MOPP's of insulation I only need 1 kV - so test wise it stacks up okay. I can take advantage of the risk management process and I may be able to use risk management to indicate a low risk, but would rather have some precedence that others have used for coatings. If I can't use a coating the design process backs way up, and major effort and headaches. Nothing's impossible but this is pretty darn close. Gary McInturff Reliability/Compliance Engineer Esterline Interface TechnologiesFeaturing ADVANCED INPUT, MEMTRON, and LRE MEDICAL products 600 W. Wilbur Avenue Coeur d'Alene, ID 83815-9496 Office:208-635-8306 Cell: 509 868 2279 Toll Free: 800-444-5923 X 1238 [email protected] www.esterline.com/interfacetechnologies Technology, Innovation, Performance... - ---------------------------------------------------------------- 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.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. 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.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. 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]>
