WorldWide Drilling Resource

39 WorldWide Drilling Resource ® AUGUST 2015 Last month, we talked about a PPC5 Drive and someone who could not get it to go over 2100 rpm. We noticed the problem was they did not have the drive to the correct fuse disconnect. This time, we will talk about a farm in Green Bay, Wisconsin. I received a call from our staff, asking if I could drive to Green Bay and solve a prob- lem the customer was having with a PPC5 drive. I called the electrician for the farm and made arrangements to meet him at a café, then I followed him to the farm. Once there, we talked about the problem which was this: the farm had to test their electric generator every month to make sure it worked. This was about a ten-minute test, but had to be performed monthly. Every month when the electric was turned back on, the PPC5 would turn the pump back on, except for this month (September). The drive was set to try to restart up to five times before tripping on overload. It failed all five attempts. This was a good thing, because if it had not failed, it would have burned the motor up. In other words, it was doing what it was supposed to. Of course, the question was why? Why was it tripping? Why didn’t it just start like the other times? And...how did they get it started if it kept tripping on overload? The answer to the question is really quite interesting. But first, where were they getting this water the pump was pumping, and what were they using it for? There was a well pump on the farm pumping freshwater to their system. The system included a chiller for the milk; and in Wisconsin, once water has passed through the chiller, it is no longer potable water - it is not fit for human consumption. It could, however, be used for washing down the barn and cows, cooling the cows, sprinkler applications, and drinking water for the cows. So when it came out of the chiller, it was collected in a 12-foot wide x 25-foot high tower. The tower had an 8-inch pipe that ran the water into the barn, into a hallway. At the end of the 8-inch pipe was a 150-gallon per minute, 7½-horsepower pump lying on its side. It was connected to a VFD (variable frequency drive) electrically and some tanks to be used for the not freshwater system. There was a crossover from the freshwater to the, we’ll call it dirty water side. Like a car that has to be push-started, when the pump didn’t start like it was supposed to, the crossover pipe was opened and pressured water was pushed through the pump turning the impeller stack. So now there was not as much amperage required to start the motor, AND voilà, it started. Next month, we’ll go inside the electrical room. Bill Bill Corey may be contacted via e-mail at michele@worldwidedrillingresource.com Green Bay Farm Part 1 by Bill Corey Pentair Water Training Institute