The usage method of mining cablesSelection of cable model

The selection of cable models is closely related to the reliability, safety, and economic feasibility of power supply. Article 467 of the Coal Mine Safety Regulations stipulates the following selection requirements for cables:

The level difference of the actual cable laying location should be compatible with the allowable cable laying level difference specified.

2. The cable should have a conductor of sufficient cross-section for protective grounding.

3. It is strictly prohibited to use aluminum wrapped cables.

4. Flame retardant cables that have passed inspection and obtained the safety mark for coal mining products must be selected.

5. The cross-section of the main cable core should meet the requirements of the power supply line load.

6. Requirements for fixed installation of high-voltage cables:

⑴ In vertical shafts or tunnels with an inclination angle of 45 ° or more, PVC insulated thick steel wire armored PVC sheathed power cables and cross-linked polyethylene insulated thick steel wire armored PVC sheathed power cables should be used.

⑵ In horizontal tunnels or shafts with an inclination angle of less than 45 °, PVC insulated steel strips or fine steel wire armored PVC sheathed power cables, cross-linked ethylene steel strips or fine steel wire armored PVC sheathed power cables should be used.

Aluminum core cables can be used in the air intake inclined shaft, underground parking lot and its vicinity, and between the central substation and the mining area substation; Copper core cables must be used in other locations.

(4) Fixed low-voltage cables should use Mw armored or unarmored cables or mobile rubber sheathed flexible cables of corresponding voltage levels.

(5) Non fixed high and low voltage cables must use rubber sheathed flexible cables that comply with the Mr818 standard. Mobile and handheld electrical equipment should use dedicated rubber sheathed cables.

(6) Cables used for lighting, communication, signaling, and control should be armored communication cables, rubber sheathed cables, or M, factory, factory type plastic cables.

(7) Aluminum cores should not be used for low-voltage cables, and aluminum cores are strictly prohibited for low-voltage cables in mining areas.

Selection of cable cross-section

The selection of cable cross-section includes the selection of high-voltage cable cross-section and low-voltage cable cross-section, with the selection of low-voltage cable cross-section being the main focus.

1. Selection of the main core wire of the cable

The low-voltage power supply lines in general mining areas are relatively long, and the current flowing through the cables during operation will cause voltage drop and heat generation. To ensure the normal operation of cables and motors, the following four principles should be followed when selecting cable cross-sections:

(1) When the cable is running normally, its actual temperature rise should not exceed the maximum temperature rise allowed by the insulation.

(2) Select based on the allowable voltage loss during cable operation.

(3) The selection of cable cross-section should meet the requirements of mechanical strength.

Mining cables refer to wire and cable products used for ground and underground equipment in coal mining industry This includes cables for coal mining machines, transport planes, communication, lighting, and signal equipment, as well as power cables for drill cables, cap light wires, and underground mobile substations.