Hi,
I think I have some of the same issues described in thread238-227276. I hope you can help.
I'm working to develop a device to monitor and control an oilwell pumpjack and its motor. My device takes its power from the 480V/3-phase supply that runs the motor. Lately I've had a rash of...
Hi All,
I'm working in a west Texas oilfield. The motor that drives the pumpjack is 460V, 3-ph, 60 HP. It is powered directly from the grid: no generators or VFDs, etc. Looking at the current to the motor on a scope, I can see a lot of 5th-harmonic (300 Hz) content distorting the current...
Hi,
Pumpjacks in the oil fields use 3-phase induction motors. During a certain portion of the pumping cycle, the weight of the falling masses can force the motor to rotate at above its synchronous speed, thereby turning it into a generator. There is a belief that this briefly (~ 1 second out of...
