Abstract: A compressed air supply system including an electric motor for driving an air compressor. An air reservoir connected to an outlet of the air compressor via a cooler. A dryer and a check valve, a pressure sensor coupled to the air reservoir for sensing the pressure therein. An unloading valve coupled to the outlet of the air compressor. A control circuit coupled to the electric motor and the unloading valve. A protective circuit coupled to the control circuit and the unloading valve for preventing the motor from starting under an overload condition and for averting the unnecessary running of the motor and driving of the air compressor.

Abstract: A compact, balanced and lightweight air compressor unit for a railroad vehicle which includes a motor-driven compressor, a suction strainer and suction silencer. The compressor and motor are interconnected by an intermediate hollow flanged mounting member which has a cross-sectional dimension that is smaller than the cross-sectional dimension of the motor and compressor. The suction strainer is located in a space between the motor and compressor and is attached to one side of the intermediate hollow mounting member while the suction silencer is located in a space between the motor and compressor and is attached to the other side of the intermediate hollow mounting member to form a substantially balanced structure which is suspended to the underside of the floor of the railroad vehicle by a plurality of resilient bumper connectors.