Circuit arrangement for shearer-loader for underground operations, equipped with a plurality of drive motors

摘要

The subject of the invention is a circuit arrangement for a shearer-loader 1 which is used in underground mining and is equipped with a plurality of drive motors 7, 8 which each has a current transformer 13 and temperature sensor 12. The current transformers 13 of all the drive motors 7, 8 are each connected directly to a common OR gate 16 via in each case one rectifier 15 and the temperature sensor 12. The said OR gate 16 outputs an output signal when a temperature sensor 12 signal occurs which indicates an unacceptable rise in the winding temperature or when one of the current transformers 13 produces a signal which exceeds the admissible value, which output signal is fed to an electronic trigger 17. The electronic trigger 17 subsequently acts on a relay 18 which is located in the switch-on circuit of the shearer-loader 1 and separates the shearer-loader 1 from the electrical mains 10 via the pilot protection 11 and, as a result, prevents unacceptable increases in the winding temperature but also prevents overloading of individual motors 7, 8. IMAGE