At the organization of water supply based on groundwater use technological modes of operation of water wells include convertible jet pumps starting modes, whose number can reach 30 puskovostanovok per hour (see Table. 1). Start convertible well jet pump is one of the worst regimes for their pumps, pipes and water-lifting of the well. Electric convertible jet pump at this time for a short time exposed to the peak load, as its start-up current, again, 4 – 7 times higher than the nominal value at a relatively low starting torque.
In addition, the jump start current creates a shock electromagnetic torque that is transmitted through the shaft of the engine to the pump impeller. Under such conditions, water-lifting the pipe string may be the maximum pressure fluctuation in the hydraulic shock, and in part – high values of the flow of water into the well from the aquifer.
At the same time to start mode is characterized by two periods:
❏ first (t1 = 0,9-0,5 s), within which there are high velocities of water influx into the well from the aquifer at the top of the filter. Also, there is a sharp change in pressure, which violates the stability zone (there is sand);
❏ second (t2 = 1-5 s) under certain conditions, accompanied by a water hammer in the pressure pipe.
To eliminate the negative effects of transients that occur at the start of convertible jet pumps, technological schemes of equipment wells. They are based on the electric (using devices that change the number of revolutions of the pump), the regulation of water supply and hydraulic convertible jet pumps (with shut-off and control valves) principles. This article focuses on the electrical component of the solution to the problem and its impact on energy use of pumping equipment.