Puls dimension pisa11 4 output din rail protection modules 24v dc 4 20a puls pisa11206212 this protection module from puls fulfills two basic functions first it distributes the current of a large power source to four lower current output channels and therefore allows for smaller wires to be used the second function is to permit only so much current on the outputs that the input voltage of this unit which corresponds to the output voltage of the power supply does not fall below 21v thi