Quote:
Originally posted by Uncle Bob
Never done it with a PC water pump, but in the field, we just crank up the voltage. It really depends what pump you are trying to oc. Most good ones now are using an magnetic field and only a shaft as the rotating part. So if you increase the field strength, theoretically it should spin faster. There are other things to consider as well, NPSH (net pump suction head) is another. Putting two pumps in line isn't a bad way to go, We do it all the time in our business, they are simply called 'booster pumps' and they can typically increase flow rates by 50% of given gpm of 'booster pump'. |
Most good ones use a magnetic field, indeed. Unfortunately, the design is such that the motor is a synchronous motor. That means that the magnetic field generated by the coil appears to the shaft to be a rotating field. Hence the speed of the shaft is governed by the frequency of the powerline.
(And hence, if you take such a pump designed for 60Hz operation, and run it off 50Hz, it'll run 17% slower!)
Yes, if you bring up the speed of the shaft, you'll also need to increase the power to ensure that enough power is going into the system to stop the shaft from falling behind! If the shaft falls behind, it's out of sync with the magnetic field, and you don't get any power transmission!
AidanII