Manual Butterfly,304/316 Turbine Butterfly Valve,Hard Manual Seal Valve,High-Temperature Steam Butterfly Valve Zhejiang Meide Machinery Co.,Ltd , https://www.meidemachinery.com
First, the choice of cable model
The choice of cable model has a lot to do with the reliability, safety, and economy of the power supply. Article 467 of the Coal Mine Safety Regulations establishes the following selection requirements for the selection of cables:
1. The level difference of the actual laying location of the cable should be compatible with the specified cable installation level difference.
2. Cables shall have conductors of sufficient cross-section for protective earthing.
3, aluminum cable is strictly prohibited.
4. Fire-retardant cables must be selected that have passed the inspection and obtained the safety signs for coal mining products.
5. The section of the main cable core should meet the requirements of the power line load.
6, fixed laying high voltage cable requirements:
(1) In shafts of wells whose shafts or inclinations are more than 45°, PVC insulated heavy steel wire armoured PVC sheathed power cables and cross-linked polyethylene insulated thick steel wire armored PVC sheathed power cables shall be used.
(2) In the roadways with horizontal lanes or inclinations less than 45°, PVC insulated steel strips or thin steel wire armored PVC sheathed power cables, cross-linked vinyl steel strips or fine steel wire armored PVC sheaths shall be used. power cable.
(3) Aluminum core cables may be used between inclined shafts in inlets, underground depots, and substations in central substations to substations in mining areas; copper core cables must be used in other locations.
(4) The fixed low-voltage cables shall be Mw-mounted or non-armored cables or mobile rubber sheathed cables of the corresponding voltage class.
(5) The non-fixed high and low voltage cables must use the rubber-sleeve flexible cables that meet the requirements of Mr818. Mobile and hand-held electrical equipment should use dedicated rubber sheathed cables.
(6) Cables for lighting, communications, signalling, and control shall use armored telecommunication cables, rubber sheathed cables, or M, factory, and factory-type plastic cables.
(7) Aluminum cores should not be used for low voltage cables, and aluminum cores for low voltage cables in mining areas are strictly prohibited.
Second, the choice of cable section
The choice of cable cross-section includes the selection of high-voltage cable cross-sections and the selection of low-voltage cable cross-sections, and the selection of low-voltage cable cross-sections is the mainstay.
1, the choice of cable main core
Generally speaking, the low-voltage power supply line in the mining area is relatively long. During the operation, the current flowing through the cable will cause pressure drop and heat. In order to ensure the normal operation of cables and motors, the following four principles should be observed when selecting cable sections:
(1) When the cable is in normal operation, its actual temperature rise shall not exceed the maximum temperature rise permitted by the insulation.
(2) Select the permissible voltage loss when working on the cable line.
(3) The cable cross-section must be selected to meet the mechanical strength requirements.
Mine cable refers to the ground equipment and underground wire and cable products used by coal mining industry. It includes cables for coal mining, transport, communications, lighting and signal equipment, as well as electric drill cables, cap lamp wires, and downhole mobile substations. The power cable and so on.
Introduction to the latest use of mining cables
Tianjin Cable Plant Rubber Cable Factory - Mine power supply system, high-voltage power supply lines generally use armored cable, and its failure rate is much lower than that of low-voltage power supply used rubber cable. The power supply in the mining area is a weak link in the power supply system and the working environment is poor. Therefore, how to select the type and cross section of the cable is related to the safety of the power supply operation. The following describes the cable selection and cable cross-section selection methods.