Cable bridge installation requirements and specification guidance
1, the cable bridge as a wiring project supporting a project, there is no specific norms and guidance, a manufacturer of the lack of generic specifications of the program, therefore, the selection process should be based on weak system of cable system, the number of reasonable selection Applicable bridge.
(1) to determine the direction: According to the building layout plan, combined with air conditioning lines and electrical pipelines and other settings, easy maintenance, and cable routing to determine the cable bridge the best route. In the interior, as far as possible along the walls of the building, columns, beams and floors erected, so the use of integrated corridor erection, should be in the pipeline side or above the parallel erection, and consider the line and branch line as far as possible to avoid cross, such as No other pipe rack borrow, you need to set up (support) column.
(2) Load calculation: Calculate the cable weight per unit length on the longitudinal section of the cable bridge trunk line.
(3) to determine the width of the bridge: according to the number of cable laying cable, cable diameter and cable spacing to determine the cable tray model, specifications, the length of the arm, the length of the pillars, spacing, bridge width and number of layers.
(4) to determine the installation method: According to the location of the installation conditions to determine the bridge fixed way, choose hanging, vertical, sidewall or mixed, connectors and fasteners are generally supporting the supply, in addition, according to the bridge Structure selection of the corresponding cover.
(5) draw the cable bridge flat, profile, local parts should also draw a space map, out of the material table.
2, if combined with the power cable bridge, the power cable and the weak cable should be straight side, the middle partition separated.
3, weak cable and other low-voltage cable combined bridge, should be strictly selected to choose a weak shielding system with weak shielding cable, to avoid interference between each other.
4, cable bridge installation requirements
(1) Slot-type large span cable bridge from the outdoor into the building, the bridge out of the slope of not less than 1/100. (2) cable bridge and electrical equipment cross, the gap between the distance of not less than 0.5m.
(3) two sets of cable bridge in the same height parallel laying, during which the net distance of not less than 0.6m. (4) in the parallel map to draw the bridge of the route, to indicate the starting point of the bridge, the end point, the corner point, the branch point and the lifting point of the coordinates or positioning size, elevation, such as drawing bridge axle side, Will be more accurate.
Straight line: indicate full length, deck number, elevation, model and specifications. Corners and branch points: specify the type and specification of the turn plate used. Lifting section: Note that changes in elevation, can also be used local large sample or profile diagram.
(5) bridge support points, such as columns, arm or non-standard support, the spacing of the frame, installation, model specifications, elevation, can be agreed on the plane list, can also be marked with different sections, Figure or large sample representation.
(6) cable cited point position and lead the way, in general, a large number of cables can be cited under the vertical bending plate and vertical pull on the shelves, a small number of cable cited under the guide plate or pipe, specify the way can lead down.
(7) cable bridge should be more than 2.2 meters above the ground, the top of the bridge from the roof or other obstacles should not be less than 0.3 meters, the bridge width should not be less than 0.1 meters, the cross-section of the bridge filling rate should not exceed 50%.
(8) When the cables in the cable tray are laid vertically, they shall be fixed on the upper part of the cable and at the distance of 1.5 meters. The horizontal, tail, turn and every interval of 3 ~ 5 Meters to be fixed.
(9) set in the ceiling, the slot cover should be kept open 80 mm vertical clearance, truncated section utilization should not exceed 50%.
(10) The cable laying in the trunking can not be lugged, the cable in the slot should be straight, the cable in the slot should be straight, try not to cross, the cable should not overflow the trunking, The corner should be tied to the fixed. The vertical trough laying cable shall be secured to the cable bracket at a distance of 1.5 m.
(11) in the horizontal, vertical bridge and vertical trunking in the laying of the line, the cable should be tied. 4 pairs of cable to 24 for the beam, 25 pairs or more trunk cable, cable and other signal cables should be based on the type of cable, cable diameter, cable core number of bundled banding. Lashing spacing should not be greater than 1.5 meters, buckle spacing should be uniform, elastic moderate.
(12) Horizontal laying of the bridge, the support spacing is generally 1.5-3m, vertical laying fixed on the building body spacing should be less than 2m.
Selection and laying of cable tray type and variety
First, the cable bridge type and variety of choice
1, the need to shield the electrical interference of the cable network or to protect the external (such as: corrosive liquid off, flammable dust and other environmental impact) requirements, should use (FB) trough-type composite anti-corrosion shielded cable tray (with cover )
2, strong corrosive environment should be used (F) class composite epoxy resin anti-corrosion flame retardant cable bridge. Arm, bracket also use the same material to improve the service life of the bridge and accessories, cable tray. In the easy fouling and other needs to cover the environment or outdoor places should be covered plate.
3, in addition to the above circumstances, according to the scene also the environment and technical requirements of the choice of tray, trough, cascade, glass anti-corrosion flame-retardant cable bridge or steel ordinary bridge. In the easy fouling and other needs to cover the environment or outdoor places should be covered plate.
4, in the public channel or outdoors across the road section, the bottom of the bottom of the cascade should be pad or in the use of the tray tray. Large span across the public channel, according to user requirements to improve the load capacity of the bridge or the use of rack.
5, large span (> 3m) to use composite bridge (FB).
6, outdoor to use composite epoxy tree finger bridge (F).
Second, the cable tray size selection
1, the width and height of the composite epoxy cable bridge is selected according to the following table, and should meet the cable really charge does not exceed the relevant standard specifications, power cable 40-50%, 50-70% of the control cable, In addition to the need to retain 10-25% of the development of the margin.
2, a variety of bending and accessories specifications should be consistent with the project layout and supporting the bridge.
3, support, hanger specifications of the choice, should be bridge specifications, layers, span and other conditions. And should meet the requirements of the load.
4, the choice of cross-sectional area of the bridge see the bridge on the cable network in any line of the maximum automatic over-current protection rated current value or set value (A) bridge cross-section allowable minimum (mm2) 0-60 12961-100 The present invention relates to a method for the preparation of a
Third, for the cable bridge support, hanger configuration
1, indoor support, hanging short span generally take 1.5-3m. Outside the vertical column in the vertical to take 6m.
2, non-straight section of the branch, hanger configuration to follow the following principles. When the width of the bridge <300mm, should be in the non-straight line and the line at the junction of 300-600m straight line side of the set a branch, hanger. When the bridge width> 300mm, in addition to meet the following conditions, in the middle of the non-linear section should also add a branch, hanger.
3, pultruded fiberglass cable bridge multi-layer set when the distance between the layers of 200,250,300,350 mm.
4, bridge section of the line every 50m should be extended expansion joints 20-30mm (metal bridge).
Fourth, the fire: the bridge required fire section, must use steel or non-flammable, flame retardant materials.
Fifth, pultruded FRP cable bridge grounding
1, the bridge system should have a reliable electrical connection and ground (only the metal bridge).
2, when allowing the use of bridge system to form a grounding trunk circuit should meet the following requirements. The connection resistance between the ends of the bridge shall not be greater than 0.00033 ohms and the grounding hole shall be removed from the insulating coating. In the 1KV and below neutral point direct grounding system, the grounding of the receiving equipment is connected to the system neutral line. When the power supply is installed, the cross-sectional area of the metal in the longitudinal direction of the bridge shall not be less than the specified value.
3, along the length of the bridge along the other laying the other side of the trunk, each paragraph (including non-straight section) bridge should be at least one point with the ground trunk reliable connection.
4, for the vibration site, in the connection of the ground parts should be installed coil.
6, the bridge system design content: bridge system engineering design and civil engineering, technology and related professional closely to determine the best layout, the design content can contain:
1, the cross-section of the bridge system. 2, the bridge system layout plan. 3, scaffolding system required straight line, bending, support, hanger specifications and the number of the list and the necessary instructions. 4, there are special requirements of non-standard technical description or schematic diagram.
7, installation: cable bridge in the middle of the night, please refer to the China Building Standard Design and Research Institute issued by the JSJT-121 National General Building Standard Design - electrical device standard Atlas "cable bridge installation."
Eight, design requirements
1, the path of the bridge system layout plan;
2, the cross-section of the bridge system.
3, the anti-corrosion materials used in the bridge system and the required through, bending, support (hanging) frame specifications and the number of specifications and the necessary instructions, connecting plates and screws, protective cap according to the above requirements by the manufacturer. 4, non-standard technical instructions or diagrams with special requirements.
First, the cable bridge type and variety of choice
1, the need to shield the electrical interference of the cable network or to protect the external (such as: corrosive liquid off, flammable dust and other environmental impact) requirements, should use (FB) trough-type composite anti-corrosion shielded cable tray (with cover ) 2, strong corrosive environment should be used (F) class composite epoxy resin anti-corrosion flame retardant cable bridge. Arm, bracket also use the same material to improve the service life of the bridge and accessories, cable tray. In the easy fouling and other needs to cover the environment or outdoor places should be covered plate. 3, in addition to the above circumstances, according to the scene also the environment and technical requirements of the choice of tray, trough, cascade, glass anti-corrosion flame-retardant cable bridge or steel ordinary bridge. In the easy fouling and other needs to cover the environment or outdoor places should be covered plate. 4, in the public channel or outdoors across the road section, the bottom of the bottom of the cascade should be pad or in the use of the tray tray. Large span across the public channel, according to user requirements to improve the load capacity of the bridge or the use of rack. 5, large span (> 3m) to use composite bridge (FB). The following are the same as the "
6, outdoor to use composite epoxy tree finger bridge (F).
Second, the specifications of choice
1, the width and height of the bridge by the table to choose, and should meet the cable really charge does not exceed the relevant standard specifications, power cable 40-50%, 50-70% of the control cable, the other need to stay 10 -25% of the style development margin. 2, a variety of bending and accessories specifications should be consistent with the project layout and supporting the bridge. 3, support, hanger specifications of the choice, should be bridge specifications, layers, span and other conditions. And should meet the requirements of the load. 4, the choice of cross-sectional area of the bridge See the bridge on the cable network in any line of the maximum automatic over-current protection of the rated current value or set value (A) bridge cross-section allowable minimum (mm2) 0-60 129 61- 100 258 101-200 452 201-400 645 401-600 968
Three, support, hanger configuration
1, indoor support, hanging short span generally take 1.5-3m. Outside the vertical column in the vertical to take 6m.
2, non-straight section of the branch, hanger configuration to follow the following principles. When the width of the bridge <300mm, should be in the non-straight line and the line at the junction of 300-600m straight line side of the set a branch, hanger. When the bridge width> 300mm, in addition to meet the following conditions, in the middle of the non-linear section should also add a branch, hanger.
3, the bridge between the multi-layer set when the distance between the center of 200,250,300,350 mm.
4, bridge section of the line every 50m should be extended expansion joints 20-30mm (metal bridge). The following are the same as the "
Fourth, fire
Requires the bridge fire section, must use steel or non-combustible, flame retardant materials. I produced the BJ Ⅲ series cable bridge are fire bridge.
Five, ground
1, the bridge system should have a reliable electrical connection and ground (only the metal bridge).
2, when allowing the use of bridge system to form a grounding trunk circuit should meet the following requirements. The connection resistance between the ends of the bridge shall not be greater than 0.00033 ohms and the grounding hole shall be removed from the insulating coating. In the 1KV and below neutral point direct grounding system, the grounding of the receiving equipment is connected to the system neutral line. When the power supply is installed, the cross-sectional area of the metal in the longitudinal direction of the bridge shall not be less than the specified value.
3, along the length of the bridge along the other laying the other side of the trunk, each paragraph (including non-straight section) bridge should be at least one point with the ground trunk reliable connection.
4, for the vibration site, in the connection of the ground parts should be installed coil.
Six, the bridge system design content
The engineering design of the bridge system should be closely matched with the civil, process and related disciplines to determine the optimum arrangement. The design content may include:
1, the cross-section of the bridge system.
2, the bridge system layout plan.
3, scaffolding system required straight line, bending, support, hanger specifications and the number of the list and the necessary instructions.
4, there are special requirements of non-standard technical description or schematic diagram.
Seven, installation
Cable bridge in the middle of the night, please refer to the China Building Standard Design and Research Institute issued by the JSJT-121 National General Building Standard Design - Electrical Installation Standard Atlas "Cable Bridge Installation" 04D701-3.
Eight, design requirements
1, the path of the bridge system layout plan;
2, the cross-section of the bridge system.
3, the anti-corrosion materials used in the bridge system and the required through, bending, support (hanging) frame specifications and the number of specifications and the necessary instructions, connecting plates and screws, protective cap according to the above requirements by the manufacturer.
4, non-standard technical instructions or diagrams with special requirements.