Actually, the pump being driven by flow was my initial guess. Of course, I have a bit of experience with controls for pumping systems.
I had an interesting diagnostics challenge a while back that involved a large pump driven by a large motor. It was in a hydraulic power unit that we had loaned a customer while we were repairing their failed power unit.
The complaint was simple: the pump will not start. Because the customer was an hours drive away, I first asked a few questions, then asked them to have their electricial check the 3 100 amp fuses in the 480 volt power feed circuit. He reported that one 100 amp fuse had failed, I suggested that he replace it and try starting the system again, He replaced the fuse and the replacement fuse failed as soon as they tried to start the motor. So now I had to head over to the customers site and find the problem. My approach was first to do a complete inspection, since that sort of short circuit shaould provide some evidence of itself. But all of the visible wiring looked good. Next, I did a resistance check at the motor terminals of the starter-overload assembly, which showed an open circuit in one phase. That was a good clue. I opened the connection box on the side of the motor and found that, because it had been assembled with the splice pressing against the cover of the box, the one connection had slowly cold-flow, penetrated the tape wrapping and contacted the box cover, short circuiting the phase to ground and evaporating part of the connection. The repair was simple, which was to cut off the damaged end, install a split-bolt splice instead of the lug and bolt splice, and tape the new connection. Then I was careful to position the wires in the splice box so that they did not press against the cover, and replaced the cover. After installing a new 100 Amp fuse, the systm started and ran correctly.
Note that I did switch off the service to the system before I started working on it.
Yes, good observation, Tim. Jennifer is right about how these Sherlock postings show some excellent deductive logic. It's not named "Sherlock" for nothing. What I find most impressive is that many of the solutions arise when the Sherlock involved refuses to make any assumptions.
By experimenting with the photovoltaic reaction in solar cells, researchers at MIT have made a breakthrough in energy efficiency that significantly pushes the boundaries of current commercial cells on the market.
In a world that's going green, industrial operations have a problem: Their processes involve materials that are potentially toxic, flammable, corrosive, or reactive. If improperly managed, this can precipitate dangerous health and environmental consequences.
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is