At 01:17 PM 7/13/99 -0700, Jerry Martin wrote: >Thank you to all who responded. > >I'm still a little unclear as to where the 500 Vac voltage comes from. >Is it called out in UL1950 or is it an NRTL determined value? > >Is the -48 Vdc considered SELV or a hazardous voltage secondary?
You're asking where they came up with the values in Table 18 - "Test Voltages for Electric Strength Tests"? Or as long as they follow the associated criteria for TNV circuits? Maybe I'm complicating the question ...
