FIELD: water supply systems of cities, towns and production plants. SUBSTANCE: method involves measuring active power consumed by electric motor from mains, and calculation of effective power on pump shaft taking into account efficiency of electric motor and pumping system working efficiency, which is measured, when pumping system operates with closed valve. Then, method involves measurement of pressure at input and output of pump, measurement of mains frequency or rotation frequency of electric motor of pump drive. Usage of water supplied by rotary pump is regulated by means of alteration of rotation frequency of electric motor of pump drive using frequency converter. Alternatively, method involves voltage alteration at electric motor, when direct current electric motors or collector alternating current electric motors are used. Usage calculation conforms to usage characteristics of pumps and depends on pumping system. The function takes into account ratio of power at pump shaft with respect to current pressure minus result of division of power by pressure produced by pumping system, which operates with closed valve, multiplied by ratio of current voltage frequency to nominal voltage frequency. Then, equation involves multiplication of resulted difference by ratio of current frequency to nominal frequency. Calculation of usage leads to step- wise alteration of mains frequency or power supply voltage until effective pressure is equal to target level. EFFECT: simplified design and increased precision of calculations, increased reliability and efficiency of usage regulation system. 6 dwg
