It is proposed at three cascade refrigerating plants before each compressor to superheat at regeneration the vapor to temperature of intermediate cooling and condensation. Than the vapor is compressed isothermal to the corresponding pressures. This will decrease the effective power of plant and the mass and size of the heat exchange apparatus, rise refrigerating coefficients of performance of the plant and improve conditions of compressors action. On example of three cascade refrigerating plant for recondensation of methane vapor which is transported by methane-carrier by cargo volume 150000 m3 it is shown, that after its modernization by proposed mode the effective power of plant decrease more than double. It permits to economize more 107 thousands kWth of  electric energy at day.