>>>>>>>>>>>>>>>>>> Ursprüngliche Nachricht <<<<<<<<<<<<<<<<<<
Am 03.11.98, 03:44:01, schrieb Jan Purwin <[email protected]> zum Thema Re: SELV/TNV-1 for T1/E1 Interface; SELV/TNV-1 for 100BaseT Ethernet: > Peter, > The T1 interface canbe either CSU or DSX as per Ul1950 third edition can > be clasified as TNV -1 > and under UL1950 requires primary overvoltage protection (this is UL > specific came out) not En60950 > If the primary protectors limit curent to 100Amp square sec and provide > current linit to 1.3 amp and > are housed in fire enclosure and protectors are UL listed to ul497a > then overvoltage test is not required. > For TNV-1 under E1 there is no category of outside wiring All E1 > circuits connect to inside wiring to NTTP (network terminating ponit) > that is demarcation point between PTT and customer equipment. There is > no overvoltage test required there. > but product must meet safety and protection for ETS 300-047. > The 100btT interface aprox 70 meters of cable (210feet) I have not seen > any ony one wiring that to exposed plant. > The interface is considered SELV under UL1950. The IEEE standard calls > for 1000V isolation but many vendors do not observe or implement layout > that meets that requirement. No one checks or verifvy that. I do not > believe that that a valid claim. > The LAN interface is not being considered ever carying TNV voltages. > Hope that answers > Regards Jan Purwin > Compliance Manger' > Xedia Corp > Peter Merguerian wrote: > > Hello Group, > > > > A. I have a customer with a T1/E1 interface. His manual states that > > the interface is a TNV-1 circuit and he states that this connection > > is intabuilding and never connected to exposed plant. > > > > Question 1 : Is his interface a TNV-1 circuit or is it really SELV? > > Question 2: If TNV-1, must he meet the Overvoltage Test or OV > > Construction Requirements or can he be exempt from these > > requirements? > > > > B. Another customer has a 100BaseT interface which he claims > > can be connected to exposed plant. > > > > Question 1: Should this be treated as SELV or TNV-1? > > Question 2: Should the circuit be subjected to the Overvoltage or > > OV Construction Requirements? > > > > Best Regards, > > PETER S. MERGUERIAN > > MANAGING DIRECTOR > > PRODUCT TESTING DIVISION > > I.T.L. (PRODUCT TESTING) LTD. > > HACHAROSHET 26, P.O.B. 211 > > OR YEHUDA 60251, ISRAEL > > > > TEL: 972-3-5339022 > > FAX: 972-3-5339019 > > E-MAIL: [email protected] > > Visit our Website: http://www.itl.co.il
