Tests of V94.2 gas-turbine units (GTU) of the first PGU-450T plant of the North-West Cogeneration Plant of St. Petersburg are described. The parameters of the GTU and the regular features of their variation are determined in a wide range of operating conditions from idle running to full load. The GTU are characterized by high pressure losses in a cycle, high values of specific power and yield factor, and low concentrations of toxic gases in combustion products at operating modes ranging from 50% load to full load. Quite high efficiencies of the turbomachines are obtained under conditions close to the design ones. The maximum power of 173 MW is attained at a temperature of –10°C and GTU efficiency of 34.5%.