Is the dS485 bus a SELV or PELV circuit? digitalSTROM Support October 05, 2018 07:33 Updated Follow The dS485 Bus is a SELV circuit, with an isolation voltage of 4kV. Related articles Which cable do you recommend according to VDE 0100-444 for the dS485 bus? Can other deviced be linked to the dS-485 bus? What is the maximum cable length for a dS485 bus? How are the dSMs and the dSS connected? Can I use a free NYM cable or control line for the dS 485 bus?