A rectifier and an electrical power facility in which the rectifier is disposed are provided that relate to the field of electromechanical technologies. The rectifier includes a rectifier circuit, a relay, and a controller. The rectifier further includes a detection resistor and a detection circuit, where the detection resistor is connected in series to a winding in the relay, a detection point of the detection circuit is set between the detection resistor and the winding, and an output end of the detection circuit is connected to the controller. When a voltage detected at the detection point of the detection circuit is abnormal, the detection circuit outputs an alarm signal to the controller, and after receiving the alarm signal, the controller stops outputting a driving signal to the driving end of the rectifier circuit.