1, underground maintenance and relocation of electrical equipment, cables and wires are not allowed. Before maintenance or relocation, you must cut off the power supply and check the gas. When the gas concentration in the roadway airflow is lower than 65438 0.0%, a test pen suitable for the power supply voltage should be used for inspection. Conductor-to-ground discharge can only be carried out after checking that there is no electricity. If there is a discharge device inside the control equipment, it is not subject to this restriction. Locking devices of all switches must be able to reliably prevent unauthorized power transmission and cover opening operation. When cutting off the power supply, the switch handle of the electric excavator must be locked, and a warning sign "No power transmission when someone is working" should be hung. Only the person who performs this work has the right to remove this card for power transmission. The operation of underground electrical equipment shall comply with the following provisions: part-time or off-duty electrical personnel shall not operate electrical equipment without authorization. When operating the main circuit of high-voltage electrical equipment, the operator must wear insulating gloves, insulating boots or stand on an insulating platform. The operating handle of hand-held electrical equipment and the parts that must be contacted when working must be well insulated. Easy-to-touch, exposed charged bodies and exposed rotating and driving parts of machinery must be equipped with protective facilities such as protective covers or fences. The distribution voltage at all levels underground and the rated voltage level of various electrical equipment shall meet the following requirements: high voltage, not exceeding10000 V. Low voltage, not exceeding1140 V. The rated power supply voltage of lighting, signal, telephone and handheld electrical equipment shall not exceed127 V. The rated voltage of the remote control cable shall not exceed 36V.
2, mining area electrical equipment using 3300V power supply, special safety measures must be formulated. When there are two or more voltages in the underground low-voltage distribution system of slag scraper, the voltage grade should be clearly marked on the low-voltage electrical equipment. The mine must be equipped with the distribution system diagram above and below the well, the layout diagram of underground electrical equipment and the layout diagram of electric power, telephone, signal, electric locomotive, etc., and the coal unloader should be filled in regularly as the situation changes. The installation positions of motors, transformers, power distribution equipment, signal devices and communication devices shall be indicated in the drawings.
3. Model, capacity, voltage, current type and other technical performance of each device. Setting value of feeder short-circuit and overload protection, rated current value of fuse melt, and two-phase short-circuit current value of farthest point of protected trunk line and branch line. Use, model, voltage, section and length of cable. Installation position of protective grounding device for small excavator.