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
