Dear Kris, For accessible parts (TS classification) we only refer to temperature at 25°C. Not required to recalculate measured temperatures to Tma.
For your example, you should record result 77°C @ 25°C ambient. We know that it is different than in IEC 60950-1. This has been discussed many times at TC108 meetings however it remains as it is. During the last TC108 meeting similar example for laptop adapter was brought up, however proposed change was not accepted. I hope it helps. Best regards, Boštjan From: Carpentier Kristiaan [mailto:[email protected]] Sent: Monday, January 13, 2020 12:50 PM To: [email protected] Subject: [PSES] Touch temperature levels Hi group, IEC62368-1 Table 38 defines touch temperature limits. Are these values absolute values nomatter which ambient? It seems some safety laboratories consider these values relative to 25C, thus allowing a recalculation to higher touch temperatures at higher Tma, other labs consider as absolute values. Examples: TS1 limit on plastic/rubber is 77C. Labs that stick to absolute values have a limit of 77C at 25C and also at Tma of 45C. Labs that allow recalculation allow 97C for Tma of 45C, which is well in line with the 95C value of IEC60950-1. Any explanatory guidance documents available? Regards, Kris - ---------------------------------------------------------------- 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]<mailto:[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://www.ieee-pses.org/list.html (including how to unsubscribe)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]<mailto:[email protected]>> Mike Cantwell <[email protected]<mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected]<mailto:[email protected]>> David Heald <[email protected]<mailto:[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://www.ieee-pses.org/list.html (including how to unsubscribe) 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]>
