Siemens sitop psu100d stabilised power supply units siemens 6ep1331 1ld00 a single output 21a 24v dc enclosed power supply with a wide range voltage input and a controlled isolated dc voltage output the power supply has comprehensive protection and monitoring including output overvoltage protection current limiting short circuit protection with electronic shutdown and auto restart siemens 6ep1331 1ld00 psu100d 504w enclosed power supply 24vdc 21a