The choice of cable model The choice of cable model has a lot to do with the reliability, safety, and economics 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 allowable level difference.
2. Cables shall have conductors of sufficient cross section for protective earthing.
3. Aluminum-coated cables are strictly prohibited.
4. The flame-retardant cable that has passed the inspection and obtained the safety mark of coal mine mining products must be selected.
5. The section of the main cable core should meet the requirements of the power line load.
6. Requirements for fixed laying of high voltage cables:
(1) In shafts and wells with shafts or inclinations of more than 45°, PVC insulated heavy steel wire armored PVC sheathed power cables, cross-linked polyethylene insulated thick steel wire armored PVC sheathed power should be used. cable.
(2) In horizontal roadways or shafts with an inclination of 45° or less, PVC insulated steel strips or thin steel wire armored PVC sheathed power cables, cross-linked vinyl steel strips or fine steel wire armored PVC shall be used. Sheathed 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. Vv cable and yjv cable difference and characteristics? What is a VV cable?
VV cable is a common type of power cable. Its function is the same as that of YJV cable. Although the overall performance is inferior to YJV cable and gradually replaced by YJV cable, because of its relatively low price, it is still available in many fields. Wide range of applications. Let's take a look at the simple parameter introduction of VV cable - [vv cable manufacturer]
VV cable [1]
VV cable full name copper (aluminum) core PVC insulated PVC sheathed power cable, an important member of the power cable, two letters V represents the insulation and sheathing material are PVC;
The inner and outer parts of the product structure are the conductor, insulation layer, filling layer, (steel tape layer) and jacket layer. Nowadays, the most commonly used conductor material on the market is a copper conductor; the insulating layer and the outer sheath material are PVC, that is, PVC plastic; the filling layer is generally some soft nylon material, in order to prevent the conductors between the inner conductors of the cable The direct contact and compression of each other; steel tape armored VV cable is VV22 cable, the role of steel tape armor is compressive, can be used for buried.
Implementation of the standard GB/T12706.1-2008;
The rated voltage is generally 0.6/1KV, or 35kv or less;
Operating temperature long-term working temperature does not exceed 70 °C, laying temperature not lower than 0 °C; short-circuit (maximum duration does not exceed 5s) the maximum allowable temperature of cable conductor is 160 °C;
The allowable bending radius is not less than 10 times the outer diameter of the cable;
Uses are generally used as power transmission hubs, often buried in the soil or laid in the indoor, channel, tunnel, the insulation distance between the lines is small, without poles and towers, occupying a small area, basically does not occupy space on the ground.
VV cable's common specification model core number includes 2 cores, 3 cores, 4 cores, 5 cores, 3+1, 3+2, 4+1;
Sections include cables from 1.5mm2 to 240mm2, such as VV3*95+1*50 cables, which represent three strands of 95 square cores plus one strand of 50 square cores. Others are synonymous.
Differences Between VV Cables and YJV Cables Although VV cables can replace YJV cables in many cases, it is difficult to discern each other in appearance, but the difference between VV cables and YJV cables is still relatively large.
First of all, we first understand the full name of them.
YJV cable full name copper (aluminum) core cross-linked polyethylene insulated PVC sheathed power cable;
VV cable full name copper (aluminum) core PVC insulated PVC sheathed power cable;
Insulation Material The insulation material used for different YJV cables is cross-linked polyethylene, while the VV cable is polyvinyl chloride material. Because the insulation of the YJV cable does not contain chlorine, a large amount of chlorine gas (chlorine is a toxic gas) will not be generated during combustion. In comparison, cross-linked polyethylene insulation has higher temperature resistance, is more environmentally friendly, and has better performance than ordinary polyvinyl chloride.
The operating temperature is different. The conventional YJV cable allows the maximum working temperature of 90°C. The shortest time (within 5 seconds) the maximum temperature does not exceed 250°C; The conventional VV cable allows the maximum operating temperature of about 65°C; when the short circuit occurs (within 5 seconds) the maximum temperature does not exceed 160 degrees Celsius. The difference in the maximum operating temperature determines that YJV has a higher current carrying capacity, and also determines that the YJV cable is superior to the VV cable in overall performance.
Operating voltage range is different Under normal circumstances, the voltage range of the YJV cable is 6~500KV, while the VV cable is 1~6KV. Therefore, VV cables are generally used in low-voltage environments, while YJV includes high- and low-pressure environments, which is why YJV cable manufacturing process requirements are higher.
Price and Lifetime The same specification and model number, the price of YJV cable is slightly more expensive than the price of VV. This may be the reason why VV cable is still alive now. However, YJV's service life is longer, and it is more heat-resistant and safer. From a long-term perspective and safety factor, using YJV cables is more cost-effective.
Finally, residents' projects are recommended to select YJV cables for safety and environmental protection. If the budget is really limited, you can choose to use VV cables in non-habitat locations and places where voltage and temperature are not required. In summary, the general trend is that YJV cable gradually replaces VV cable.
1. The level difference of the actual laying location of the cable should be compatible with the specified cable allowable level difference.
2. Cables shall have conductors of sufficient cross section for protective earthing.
3. Aluminum-coated cables are strictly prohibited.
4. The flame-retardant cable that has passed the inspection and obtained the safety mark of coal mine mining products must be selected.
5. The section of the main cable core should meet the requirements of the power line load.
6. Requirements for fixed laying of high voltage cables:
(1) In shafts and wells with shafts or inclinations of more than 45°, PVC insulated heavy steel wire armored PVC sheathed power cables, cross-linked polyethylene insulated thick steel wire armored PVC sheathed power should be used. cable.
(2) In horizontal roadways or shafts with an inclination of 45° or less, PVC insulated steel strips or thin steel wire armored PVC sheathed power cables, cross-linked vinyl steel strips or fine steel wire armored PVC shall be used. Sheathed 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. Vv cable and yjv cable difference and characteristics? What is a VV cable?
VV cable is a common type of power cable. Its function is the same as that of YJV cable. Although the overall performance is inferior to YJV cable and gradually replaced by YJV cable, because of its relatively low price, it is still available in many fields. Wide range of applications. Let's take a look at the simple parameter introduction of VV cable - [vv cable manufacturer]
VV cable [1]
VV cable full name copper (aluminum) core PVC insulated PVC sheathed power cable, an important member of the power cable, two letters V represents the insulation and sheathing material are PVC;
The inner and outer parts of the product structure are the conductor, insulation layer, filling layer, (steel tape layer) and jacket layer. Nowadays, the most commonly used conductor material on the market is a copper conductor; the insulating layer and the outer sheath material are PVC, that is, PVC plastic; the filling layer is generally some soft nylon material, in order to prevent the conductors between the inner conductors of the cable The direct contact and compression of each other; steel tape armored VV cable is VV22 cable, the role of steel tape armor is compressive, can be used for buried.
Implementation of the standard GB/T12706.1-2008;
The rated voltage is generally 0.6/1KV, or 35kv or less;
Operating temperature long-term working temperature does not exceed 70 °C, laying temperature not lower than 0 °C; short-circuit (maximum duration does not exceed 5s) the maximum allowable temperature of cable conductor is 160 °C;
The allowable bending radius is not less than 10 times the outer diameter of the cable;
Uses are generally used as power transmission hubs, often buried in the soil or laid in the indoor, channel, tunnel, the insulation distance between the lines is small, without poles and towers, occupying a small area, basically does not occupy space on the ground.
VV cable's common specification model core number includes 2 cores, 3 cores, 4 cores, 5 cores, 3+1, 3+2, 4+1;
Sections include cables from 1.5mm2 to 240mm2, such as VV3*95+1*50 cables, which represent three strands of 95 square cores plus one strand of 50 square cores. Others are synonymous.
Differences Between VV Cables and YJV Cables Although VV cables can replace YJV cables in many cases, it is difficult to discern each other in appearance, but the difference between VV cables and YJV cables is still relatively large.
First of all, we first understand the full name of them.
YJV cable full name copper (aluminum) core cross-linked polyethylene insulated PVC sheathed power cable;
VV cable full name copper (aluminum) core PVC insulated PVC sheathed power cable;
Insulation Material The insulation material used for different YJV cables is cross-linked polyethylene, while the VV cable is polyvinyl chloride material. Because the insulation of the YJV cable does not contain chlorine, a large amount of chlorine gas (chlorine is a toxic gas) will not be generated during combustion. In comparison, cross-linked polyethylene insulation has higher temperature resistance, is more environmentally friendly, and has better performance than ordinary polyvinyl chloride.
The operating temperature is different. The conventional YJV cable allows the maximum working temperature of 90°C. The shortest time (within 5 seconds) the maximum temperature does not exceed 250°C; The conventional VV cable allows the maximum operating temperature of about 65°C; when the short circuit occurs (within 5 seconds) the maximum temperature does not exceed 160 degrees Celsius. The difference in the maximum operating temperature determines that YJV has a higher current carrying capacity, and also determines that the YJV cable is superior to the VV cable in overall performance.
Operating voltage range is different Under normal circumstances, the voltage range of the YJV cable is 6~500KV, while the VV cable is 1~6KV. Therefore, VV cables are generally used in low-voltage environments, while YJV includes high- and low-pressure environments, which is why YJV cable manufacturing process requirements are higher.
Price and Lifetime The same specification and model number, the price of YJV cable is slightly more expensive than the price of VV. This may be the reason why VV cable is still alive now. However, YJV's service life is longer, and it is more heat-resistant and safer. From a long-term perspective and safety factor, using YJV cables is more cost-effective.
Finally, residents' projects are recommended to select YJV cables for safety and environmental protection. If the budget is really limited, you can choose to use VV cables in non-habitat locations and places where voltage and temperature are not required. In summary, the general trend is that YJV cable gradually replaces VV cable.
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