A refrigerated vehicle (2;4;6;8) having at least one refrigerated compartment, comprising: at least one electrical power supply; and a refrigeration unit having: a first module mounted on the exterior of a refrigerated compartment, the first module comprising: a compressor having a discharge port and a suction port and further having a motor hermetically disposed therein for running the compressor, the motor being electrically connected to the at least one electrical power supply; a condenser heat exchanger operatively coupled to the compressor discharge port; and at least one condenser fan assembly having at least one electric fan motor configured to provide air flow over the condenser heat exchanger; and a second module mounted on the interior of a refrigerated compartment, the second module comprising: an evaporator heat exchanger operatively coupled to the compressor suction port; and at least one evaporator fan assembly having at least one electric motor configured to provide air flow over the evaporator heat exchanger; the at least one electrical power supply comprising at least one AC electrical power supply for providing AC electrical power to the refrigeration unit, the at least one AC electrical power supply comprising an alternator or generator assembly that is operatively coupled to the engine of the vehicle; characterised in that: the first module of the refrigeration unit comprises a power converter comprising means for converting AC electrical power into AC power at one or more different voltages and/or frequencies electrically connected to the alternator or generator assembly and arranged to provide electrical power to the motor of the compressor.. at least one electrical power supply; and a refrigeration unit having: a first module mounted on the exterior of a refrigerated compartment, the first module comprising: a compressor having a discharge port and a suction port and further having a motor hermetically disposed therein for running the compressor, the motor being electrically connected to the at least one electrical power supply; a condenser heat exchanger operatively coupled to the compressor discharge port; and at least one condenser fan assembly having at least one electric fan motor configured to provide air flow over the condenser heat exchanger; and a second module mounted on the interior of a refrigerated compartment, the second module comprising: an evaporator heat exchanger operatively coupled to the compressor suction port; and at least one evaporator fan assembly having at least one electric motor configured to provide air flow over the evaporator heat exchanger; the at least one electrical power supply comprising at least one AC electrical power supply for providing AC electrical power to the refrigeration unit, the at least one AC electrical power supply comprising an alternator or generator assembly that is operatively coupled to the engine of the vehicle; a first module mounted on the exterior of a refrigerated compartment, the first module comprising: a compressor having a discharge port and a suction port and further having a motor hermetically disposed therein for running the compressor, the motor being electrically connected to the at least one electrical power supply; a condenser heat exchanger operatively coupled to the compressor discharge port; and at least one condenser fan assembly having at least one electric fan motor configured to provide air flow over the condenser heat exchanger; and a compressor having a discharge port and a suction port and further having a motor hermetically disposed therein for running the compressor, the motor being electrically connected to the at least one electrical power supply; a condenser heat exchanger operatively coupled to the compressor discharge port; and at least one condenser fan assembly having at least one electric fan motor configured to provide air flow over the condenser heat exchanger; and a second module mounted on the interior of a refrigerated compartment, the second module comprising: an evaporator heat exchanger operatively coupled to the compressor suction port; and at least one evaporator fan assembly having at least one electric motor configured to provide air flow over the evaporator heat exchanger; the at least one electrical power supply comprising at least one AC electrical power supply for providing AC electrical power to the refrigeration unit, the at least one AC electrical power supply comprising an alternator or generator assembly that is operatively coupled to the engine of the vehicle; an evaporator heat exchanger operatively coupled to the compressor suction port; and at least one evaporator fan assembly having at least one electric motor configured to provide air flow over the evaporator heat exchanger; the at least one electrical power supply comprising at least one AC electrical power supply for providing AC electrical power to the refrigeration unit, the at least one AC electrical power supply comprising an alternator or generator assembly that is operatively coupled to the engine of the vehicle;