A duplicated system comprises two identical circuits, each designed for full load, with the changeover to standby power provided automatically. A sectionalizer, when one of the circuits is damaged, automatically connects the consumer to the serviceable circuit. ...

As it is known, the load of downhole electric motors has a sharply variable character. When calculating the cable network should be based on the maximum performance of downhole machines and mechanisms. Therefore, the choice of the mode of calculation of the sectional cable network is especially important. For this purpose it is necessary to know the required voltage at different modes of operation of the main engine, which in the conditions of the coal mine site is the engine of the shearer or shearer machine.