Please help to settle an arguement . At work we use 125v DC for relaying and controls . The company buys two conductor cable for the input source to the devices . The cable has a black and a white conductor , and engineering specs black as positive and white as negative . One of my co workers swears that white should ALWAYS be positive and claims that there are standards that back him up , but I've never seen anything . Is anyone familiar with some code or standard that specs white as positive ? He says it's ANSI or IEEE , etc.