It is an instrument for voltage monitoring and protection of refrigerated transport. This instrument protects the refrigeration system compressor from under and over-voltage, modular and angular asymmetry and even phase fault and invertion. It selects the arrangement of motor winding coils using a specific output, such that the motor can receive the local voltage, ensuring the compressor is connected to the correct power mains. If the voltage is 220V, this product powers a contactor the configures the motor coils in connection. It features a digital input to identify whether the system is operating from the diesel generator or the electric power. It has an internal memory (datalogger), which allows recording of the dates and times when the cooling system was connected to the electric power.