WorldWide Drilling Resource

55 WorldWide Drilling Resource ® JUNE 2015 Wouldn’t Go Over 2100 Part 1 by Bill Corey Pentair Water Training Institute We received a call from a customer who said he installed a PPC5 Drive and couldn’t get it to go over 2100 rpm. So another rep, Scott, and I got in Scott’s van and headed out. We got there, and as we pulled into the drive of the strip mall, I noticed we followed along the road rather than to the buildings. As we moved along the road, I saw a large cement block maybe eight inches square and I thought: Why are we going over here? Then I saw a smaller block on the big one and thought: No, they wouldn’t put a drive in a pit. Oh yes they did, and it had eight inches of water in it. The installer dropped a sump pump in the pit and drained it out, then jumped down on the boards he set down there. He obviously knew the pit would flood. He removed the keypad from the drive and handed it to us. We had a computer cord we plugged into the back of the keypad and gave the other end to him to plug into the drive. We hit the ON button and watched to see it indeed went to 2100 rpm and stayed there, wouldn’t go over. Scott said to me, “There are two modes the drive runs in - Scalar and Vector. You normally run it in Vector mode because in Vector mode it will react very quickly to what is going on. In Scalar mode, however, it reacts slowly to what is happening, so let’s see what happens.” He set the drive to Scalar. While he did that, I asked the salesman who sold the drive to the installer what the voltage was there, and he said a good strong 230 volts. Okay. Scott hit the ON button again, and that time the drive tripped on over cur- rent immediately. While he put it back to Vector, I asked the salesman again what voltage he had, and again he said a good strong 230 volts. After Scott set the drive back to Vector mode, he told me the DC Bus should read about 100 volts more than the input voltage. So we took a look at the DC Bus. The formula for this is 1.414 times the input voltage. It of course said 285 volts, and again I asked what voltage he had, to which I received the same answer as before “a good strong 230 volts”. That time I said I didn’t believe him and asked the installer if he had a voltage meter. He did. The conclusion next month! Bill Bill Corey may be contacted via e-mail at michele@ worldwidedrillingresource.com On June 6, 1944, D-Day included classified artificial harbors, codenamed Mulberrys, using jack-up rig technology.