The paper deals with the equipment and construction of modern high-power testing laboratory capable of testing circuit breakers of ratings up to 1 500 MVA at voltages up to 132 kV.General details of the power circuit are given, including the generator, super-excitation system, load and power factor control, step-up and step-down transformers, and switchgear.The metering and instrument equipment is also described, particulars being given of both low- and high-frequency oscillographs and their associated components.