Hi Aldous, ----- Original Message ----- From: "Aldous, Scott" <[email protected]>
> PTCs have a max. current limit standard fuses also > Why don't you use fault testing to determine acceptability of that portion > of the circuit that is not LPS? Method 2 of clause 4.7.1 allows this. I supposed it should be possible to design 12V/0.3A device needing no testing. > Clause 4.7.2 does not require a fire enclosure for nonLPS circuits where > fault testing shows that temperatures sufficient for ignition are not > present (see also 4.7.2.2). Pick the worst case/highest output current > power supply your product could be connected to for your test. Once again, > this requires an instruction in the manual that the supply used cannot be > cable of providing more current than the supply used for the test. If I write that power supply can be 12V and up to 5A isn't it the same as asking for LPS power supply ? As a designer I'd like to be 100% sure of my design before testing and I'm looking for instructions in 60950-1. I don't know how high the temperature can rise if there is shortage in the socket destined for powering the device (with 5A thin cables can be the source of hi hitting). I understand (may be wrongly) that socket (terminal block) is the element and like other elements I should consider it being shorted. In my (certainly not expert) opinion if the distance between terminal blocks for + and for - is enough big (don't know how big) and + is directly connected to 1A fuse (having the right certifications), and whole fuse is in enough distance from - than device should be 100% fire save, but I didn't found that in 60950-1. Best Regards Piotr Galka - 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]>
