Mine engineering considerations mine project is not a single, each system do mine project should be safe when they are to do the actual situation, this paper introduces the power supply system, grounding systems, surveillance systems, telephone systems, network systems, and Wiring requirements,
Monitor lightning precautions
a) Do not install lightning rods on outdoor signal equipment to avoid lightning strikes.
b) Outdoor signal equipment should not be installed on outdoor lightning rods and lightning protection towers as much as possible to prevent direct lightning strikes and strong induced lightning on signal lines and equipment internal circuits.
c) When the signal equipment must be installed on the top of the tallest building, it must adopt independent measures to prevent direct lightning strikes, but the direct lightning strike ground wire must be separated from the ground of the signal lightning protection device of the anti-inductive lightning, and the signal lightning protection device must not be directly used. The ground wire is connected with the lightning protection belt.
5) In order to ensure the lightning protection effect, it is necessary to install corresponding surge protectors for solid core lines such as power lines and telephone lines, and perform equipotential bonding, wiring, and grounding according to standards.
Grounding system considerations
1) Lightning protection grounding must be less than 4 ohms, and when using common grounding, it should be less than 1 ohm.
2) The distance between two independent grounds must be greater than 20 meters, or else equal equalizers are installed between the two places.
3) The signal lightning protector should be separated from the direct lightning strike as much as possible so as to prevent direct lightning from counterattacking the signal equipment from the ground.
4) Outdoor grounding device:
A galvanized flat iron buried horizontally composes the ground net, buried no less than 1 meter.
B artificial grounding module buried, buried not less than 0.5 meters.
C2.5 meters of galvanized steel brazing vertical into the ground, more than one, the mutual spacing must be greater than 5 meters.
D2.5 meters galvanized steel brazed galvanized flat iron mesh.
Based on the above E method, add a resistance reducing agent or change soil.
5) The outdoor grounding lead must be welded with the buried grounding device and be used for anti-corrosion treatment (brushing asphalt, etc.)
6) The indoor grounding and equipotential must be soldered or mechanically connected. The paint or oxide layer at the joint must be removed before connection.
7) Wire diameter of the grounding lead: Lead from the equipment room to the outdoor grounding device (round steel diameter should be greater than 10mm, flat steel section should be greater than 80mm2).
8) The copper wire and the flat iron must be welded or mechanically connected and used for anti-corrosion treatment.
Network system lightning precautions
1) All lightning protectors must be grounded and meet national standards.
2) The network cable and RJ45 connector should be regular products with correct wire sequence and good connector manufacturing.
3) The connection line between the arrester and the protected equipment should be as short as possible and should not exceed 0.5m.
4) In order to ensure the lightning protection effect, corresponding lightning protection devices shall be installed on the solid core lines such as power lines and network lines, and equipotential bonding, wiring, and grounding shall be performed in accordance with standards.
Wiring requirements
1) The entire wiring must be shielded or buried and grounded at both ends of the shield.
2) Lines entering and exiting buildings must be buried and shielded. Absolutely prohibited from entering and exiting overhead.
3) The wiring must be far away from the telephone or other power supply and other lines to prevent other induction effects on the line without lightning protection from generating secondary induction on the signal line. The standard requirements refer to the national standard GB50198-94.
4) When the optical fiber with a metal reinforcing core is used for signal transmission, both ends of the metal reinforcing core should be grounded.
Telephone system lightning precautions
1) The Cologne structure telephone lightning protector LSA10G-230 can be directly inserted into the Cologne structure. Since the grounding of the lightning protector is based on the metal housing of the Cologne structure frame, it is necessary to confirm whether the frame grounding is good.
2) All lightning protection devices must be grounded and meet national standards.
3) The telephone lightning arrester RJ45-TELE/2S is universal for RJ45 and RJ11. The protection lines are the two middlemost lines. The RJ45 connectors are 4, 5 lines, and the RJ11 is 2, 3 lines.
4) The connecting line between the arrester and the equipment to be protected should be as short as possible and should not exceed 0.5m.
Power supply system lightning precautions
1) Power supply circuits in the equipment room must be equipped with three or more power lightning protection devices.
2) The distance between the first stage SPD (low voltage surge protector) and the second stage SPD should be greater than 10m, and the distance between the second stage and the third stage should be greater than 5m. Otherwise, coordination inductance should be added.
3) Before the lightning protection module must be connected in series with open or fuse protection, to prevent the short circuit of the main circuit to ground when the lightning protection device fails, and the current setting of the air opening and the fuse is matched: first grade (63A), second grade ( 32A), three levels (16A), but generally do not exceed the previous stage fuse.
4) The power surge protector must be connected to the output terminal of the main circuit breaker and paralleled to ground.
5) The connecting lead of the power surge protector should be less than 0.5 meters and should be short and straight.
6) The power supply lightning protection input terminal wire diameter is: one (16mm2), two (10mm2), three (6mm2), power output to ground lead wire diameter: a (25mm2), two (16mm2), Three levels (10mm2).
7) The connecting wire of the power surge protector should not be bent at a right angle or at an acute angle, and should be bent at an obtuse angle as much as possible.
8) The lead of the power lightning protector should be distinguished by the line color as far as possible, and should be mechanically connected.
9) The resistance of the power supply PE should not be greater than 4Ω, and the common ground should be less than 1Ω.
to sum up
The implementation of lightning protection projects must meet the norms, so as to make a truly good lightning protection system, play a role in the protection of the equipment.
Monitor lightning precautions
a) Do not install lightning rods on outdoor signal equipment to avoid lightning strikes.
b) Outdoor signal equipment should not be installed on outdoor lightning rods and lightning protection towers as much as possible to prevent direct lightning strikes and strong induced lightning on signal lines and equipment internal circuits.
c) When the signal equipment must be installed on the top of the tallest building, it must adopt independent measures to prevent direct lightning strikes, but the direct lightning strike ground wire must be separated from the ground of the signal lightning protection device of the anti-inductive lightning, and the signal lightning protection device must not be directly used. The ground wire is connected with the lightning protection belt.
5) In order to ensure the lightning protection effect, it is necessary to install corresponding surge protectors for solid core lines such as power lines and telephone lines, and perform equipotential bonding, wiring, and grounding according to standards.
Grounding system considerations
1) Lightning protection grounding must be less than 4 ohms, and when using common grounding, it should be less than 1 ohm.
2) The distance between two independent grounds must be greater than 20 meters, or else equal equalizers are installed between the two places.
3) The signal lightning protector should be separated from the direct lightning strike as much as possible so as to prevent direct lightning from counterattacking the signal equipment from the ground.
4) Outdoor grounding device:
A galvanized flat iron buried horizontally composes the ground net, buried no less than 1 meter.
B artificial grounding module buried, buried not less than 0.5 meters.
C2.5 meters of galvanized steel brazing vertical into the ground, more than one, the mutual spacing must be greater than 5 meters.
D2.5 meters galvanized steel brazed galvanized flat iron mesh.
Based on the above E method, add a resistance reducing agent or change soil.
5) The outdoor grounding lead must be welded with the buried grounding device and be used for anti-corrosion treatment (brushing asphalt, etc.)
6) The indoor grounding and equipotential must be soldered or mechanically connected. The paint or oxide layer at the joint must be removed before connection.
7) Wire diameter of the grounding lead: Lead from the equipment room to the outdoor grounding device (round steel diameter should be greater than 10mm, flat steel section should be greater than 80mm2).
8) The copper wire and the flat iron must be welded or mechanically connected and used for anti-corrosion treatment.
Network system lightning precautions
1) All lightning protectors must be grounded and meet national standards.
2) The network cable and RJ45 connector should be regular products with correct wire sequence and good connector manufacturing.
3) The connection line between the arrester and the protected equipment should be as short as possible and should not exceed 0.5m.
4) In order to ensure the lightning protection effect, corresponding lightning protection devices shall be installed on the solid core lines such as power lines and network lines, and equipotential bonding, wiring, and grounding shall be performed in accordance with standards.
Wiring requirements
1) The entire wiring must be shielded or buried and grounded at both ends of the shield.
2) Lines entering and exiting buildings must be buried and shielded. Absolutely prohibited from entering and exiting overhead.
3) The wiring must be far away from the telephone or other power supply and other lines to prevent other induction effects on the line without lightning protection from generating secondary induction on the signal line. The standard requirements refer to the national standard GB50198-94.
4) When the optical fiber with a metal reinforcing core is used for signal transmission, both ends of the metal reinforcing core should be grounded.
Telephone system lightning precautions
1) The Cologne structure telephone lightning protector LSA10G-230 can be directly inserted into the Cologne structure. Since the grounding of the lightning protector is based on the metal housing of the Cologne structure frame, it is necessary to confirm whether the frame grounding is good.
2) All lightning protection devices must be grounded and meet national standards.
3) The telephone lightning arrester RJ45-TELE/2S is universal for RJ45 and RJ11. The protection lines are the two middlemost lines. The RJ45 connectors are 4, 5 lines, and the RJ11 is 2, 3 lines.
4) The connecting line between the arrester and the equipment to be protected should be as short as possible and should not exceed 0.5m.
Power supply system lightning precautions
1) Power supply circuits in the equipment room must be equipped with three or more power lightning protection devices.
2) The distance between the first stage SPD (low voltage surge protector) and the second stage SPD should be greater than 10m, and the distance between the second stage and the third stage should be greater than 5m. Otherwise, coordination inductance should be added.
3) Before the lightning protection module must be connected in series with open or fuse protection, to prevent the short circuit of the main circuit to ground when the lightning protection device fails, and the current setting of the air opening and the fuse is matched: first grade (63A), second grade ( 32A), three levels (16A), but generally do not exceed the previous stage fuse.
4) The power surge protector must be connected to the output terminal of the main circuit breaker and paralleled to ground.
5) The connecting lead of the power surge protector should be less than 0.5 meters and should be short and straight.
6) The power supply lightning protection input terminal wire diameter is: one (16mm2), two (10mm2), three (6mm2), power output to ground lead wire diameter: a (25mm2), two (16mm2), Three levels (10mm2).
7) The connecting wire of the power surge protector should not be bent at a right angle or at an acute angle, and should be bent at an obtuse angle as much as possible.
8) The lead of the power lightning protector should be distinguished by the line color as far as possible, and should be mechanically connected.
9) The resistance of the power supply PE should not be greater than 4Ω, and the common ground should be less than 1Ω.
to sum up
The implementation of lightning protection projects must meet the norms, so as to make a truly good lightning protection system, play a role in the protection of the equipment.
Aromatic Compound, any of a large class of compounds that includes benzene and compounds that resemble benzene in certain of their chemical properties. Originally applied to a small class of pleasant-smelling chemicals derived from vegetables, it now encompasses a wide diversity of compounds with no connection to the sense of smell. Common aromatic compounds other than benzene include toluene, naphthalene, and anthracene (all of which are present in coal tar). Each of these compounds contains at least one ring that consists of six carbon atoms, each joined to at least two other carbon atoms, and each joined to adjacent carbon atoms by one single and one double bond. The resulting hexagonal structure is characteristic of many aromatic compounds
Aromatic Compound
Aromatic Compound,1-Bromo-3-Methylbenzaldehyde
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