| 摘要 |
A device for protection against leakage currents in mine electric networks comprises a unit for insulation control and containing a source of measurement direct current, a with phases and ground containing a compensating throttle with a control unit and a ; a unit for comparing measurement and reference currents, a measurement relay, a unit for detection of network phase with , which is connected to an ; which contacts are connected between the corresponding network phase and grounder. An auxiliary AC winding is located on the ing throttle of the network connection unit; the primary winding of the throttle is connected to zero point of secondary windings of the power transformer feeding the protected network. The output of measurement relay is connected to a of a switch which supplies voltage to said power transformer, a unit for comparison of auxiliary winding voltage and reference voltage is introduced to the device, to which output an auxiliary relay is connected, one contact of the relay is connected to the shut-down circuit of switch, the second contact - to the control circuit of the actuating relays which grounds the network phase with defective insulation. |
