Hi Colin & Treg As this is an industry standard set of definitions, I do not think I am breaking any IEC copywright in answering. The definitions can be found in either IEC or EN 60950 :1992 with Amd 1 to 5. For thoses who haven't bought the standard:
TNV 1 = A Telecom Network Voltage source whose normal operating voltages do not exceed SELV limits. Overvoltages are possible from the Telecom Network TNV 2 = As TNV1 Except that Overvoltages are NOT possible from the Telecom Network. TNV 3 = A TNV source whose voltages exceed the normal limits for SELV under normal operation. Overvoltages are possible from the Telecom Network. SELV = Safety Extra Low Voltage. (No further definition given as this has been in use for many years) PTO's must declare their network safety status and currently (pre April 2000 when everything changes) a notified body should be able to advise on this status. Best regards: Bill Ellingford, Motion Media Technology Ltd ---------- From: [email protected][SMTP:[email protected]] Sent: 27 September 1999 10:52 To: [email protected] Hello, Can someone help me by giving me a reference or a definition of TNV-2 and TNV-3 circuits. Thanks and regards, Colin. Colin McGeechan, ------------------------------------------------------------------------- Product Regulations Specialist, Hewlett-Packard Ltd, TNTD, South Queensferry, West Lothian, Scotland EH30 9TG Tel: +44 131 331 7196 FAX: +44 131 331 7150 email: [email protected] -------------------------------------------------------------------------
