SELV Question

[Robert Tims]

Hello All,
I have a question about classifying the CO power environment:
Would one consider the -48VDC power supplied by the CO to be a SELV
circuit as defined in EN60950/UL1950 etc?
How is the DC circuit isolated from the mains supply?
Thanks in advance, and
Happy Holidays,
Bob Tims
Compliance Engineer
Ericsson Messaging Systems Inc.
robert.t...@ericsson.com