so would this mean what if you perform IEC/EN60950-1 testing for CB report in US or China/Taiwan/or anywhere else in the world, but not in UK or EU, then the tests will be slightly inadequate? because if standard does not specify exact environment and test is done in completly different conditions, with either simple converter of existing voltage supply (which clearly will no exibit any charachteristic impedance or waveform distortion of UK ring) or dedicted power supply. on a note of testing open sample, just PCB without enclosure. How does this makes it worst case or any case? If fuse get destroyed, traces evaporated, but no fire, when it will be pass. But if you take the same sample, put in enclosure, perfrom the test, enclosure comes open, it is a failure. this is the note from 60950:
NOTE If fuses complying with IEC 60127 are used in PRIMARY CIRCUITS, they should have high breaking capacity (1 500 A) if the prospective short-circuit current exceeds 35 A or 10 times the current rating of the fuse, whichever is greater So does this mean if you use any other fuse/device (which does not comply with IEC60127), when you do not have to chooose 1500A breaking capacity fuse? The whole section 2.7.3 is full with halfxxx statements and incomplete assumptions. Mark > Date: Thu, 21 May 2009 18:08:12 +0100 > To: [email protected] > From: [email protected] > Subject: Re: IEC 60950-1 short circuit test criteria > > In message > <[email protected]>, Ralph > McDiarmid <[email protected]> writes > > >We do have problems with mains harmonic currents in 120/240V, 3-wire > >distribution system and there are harmonic emission limits for grid-tie > >inverters connecting to the public utility at low voltage. > > Yes, I meant that problems you have are less severe, excluding hot > neutrals. We have voltage waveform distortion, due to the higher supply > impedances. > -- > This is my travelling signature, adding no superfluous mass. > John M Woodgate > > - > ---------------------------------------------------------------- > 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]> ________________________________ Hotmail® has ever-growing storage! Don’t worry about storage limits. Check it out. <http://windowslive.com/Tutoria /Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage1_052009> - 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]>
