The technical diagnostics of the electrical compressor is proposed basing on the control of electromagnetic processors in induction electric motor. The crankshaft of the compressor if hardly connected with the shaft og the motor. Therefore the present technical condition of the compressor (uneven angular velocity and acceleration, time moments of on and off of the valves, ageing of the bearings, etc.) is determined with the spectral distribution of the current consumed by the motor against the rotation angle of the compressor crankshaft. Thus the induction motor is constantly operating in the dynamic regime. The dynamic regime of the electric drive is well to be analysed by means of vector model. A widely applied on board the vessels operation cycle of double-stage compressor is considered for the investigation.