Hello George: If you fail the high pot test. You should refer to your transformer manufacturer to see if they are IEC950/EN60950 compliant or not. For instance IEC 950 calls for Australian high pot test of 2.5 KV if you have 1.5 KV transformer, then your are more likely susceptible to failure. Also the minimum required distance for creepage clearance for Nordic countries is 2.5 mm while the rest of the world is 1.4 I would suggest look into your art work for the SELF circuit/TNV for meeting these minimum creepage clerance distances. 2.5 mm minimum creepage distance is required as a normal practice to pass the high pot/voltage breakdown test successfully.
Best Regards, Nezam Najafi Sr. Compliance Engineer Madge Networks, Inc. -----Original Message----- From: sparaci...@andovercontrols.com [mailto:sparaci...@andovercontrols.com] Sent: Thursday, July 01, 1999 9:00 AM To: emc-p...@ieee.org Subject: Hipot requirements 4 TNV circuits Hello Once Again .. Everyone, I have a modem product that failed the hipot requirement defined in cls 6 of 950. My understanding is that an isolation xfmr between Telco & SELV is needed and clearance from Telco & gnd is to be 3mm minimum. Does anyone have any other general design guidelines that they can share on this topic ? Also, Can anyone point me to any manufacturers app notes for components used for telco isolation ? And if anyone can recommend any reading material, I'd like to read up on these and other issues relating to compliance design aspects of Telco circuits. Thanks, George --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
