Currently, we have a product undergoing UL60950 approval and there seems to be some debate about the classification of the TNV voltages. Our product has the following TNV circuits: T1, a POTS modem line and DSL w/span power (up to 190Vdc). The approval agency is classifying the circuits as follows: T1 - TNV-1, POTS - TNV-3 and DSL - Hazardous Voltage secondary circuit.
My question is; by definition, shouldn't the DSL circuits fall under the TNV-3 and not Hazardous Voltage secondary circuit. The major difference is when you are determining the creepage and clearance distances. At TNV-3 you are allowed basic insulation between TNV-3 circuits and SELV circuits but at the Haz Voltage Reinforced insulation is required. Thanks, Perry Hopkins Conklin Corporation Ph: (770) 662-0317 FAX: (770) 662-0319
