Installing, Operating, and Maintaining dc Motors in a Paper Mill Environment: Using Proactive Measures That Promote Longevity

To paraphrase the son of lady macduff in william Shakespeare's Macbeth, "DC is not dead, for all your saying!" When the paper industry was first electrified, the only type of machine capable of variable-speed operation was powered by dc. There were numerous manufacturers and users who knew how the machines worked and how to maintain them. Over time, the control of these machines has changed from relatively simple analog to complex digital systems. Those whose task it was to keep the machines healthy have since moved on to other things. The modern pulp, paper, and forest industries still have applications powered by dc equipment; however, the most recent installation trend is toward ac machines.