High speed switch automatic check protecting device for direct current electric locomotives

The invention relates to a high speed switch automatic check protecting device for direct current electric locomotives, belongs to mining direct current electric locomotive power supply equipment, and particularly relates to a protecting device for electric leakage or short circuit of a power supply main loop of the electric locomotive. The device is characterized in that a iron stand is insulated against ground; a high-pressure sampling circuit is connected in series between the iron stand and the ground; a detection protective circuit with a detection button and comprising a sampling unit circuit, an executing unit circuit and an experiment detecting unit circuit and a breakdown displaying circuit with a reset button are arranged on the sampling circuit; when the breakdown occurs, the sampling circuit produces a signal; one path of signals drive a relay to work; the high speed switch is turned off to protect the main loop; and the other path of signals lighten an LED (Light Emitting Diode)light to alarm. Th