Is there a national specification for the installation of metal cable trunking?

Legal analysis: 1. Irradiated cross-linked power cable (voltage level: ; Executive standard: GB

2. Medium voltage XLPE insulated power cable (voltage level: 6 6kv-26 35kv; Executive standard: GB

3. High-voltage XLPE insulated power cable (voltage level: 64 110kV, executive standard: GB T 11017-[B]2002;127/220kv、290/500kv）

Fourth, the control cable (executive standard: GB9330-88; Voltage level: 450 750V).

5. Computer cable (voltage level: enterprise standard).

6. Overhead insulated cable (voltage level: ; Executive standard: three).

7. Aluminum stranded wire and steel-core aluminum stranded wire (voltage level: ; Executive standard: GB T 1179-1999).

8. Fire-resistant cable (voltage level: ; Executive standard: GB T 19666-2005, GB

9. Low-smoke halogen-free cable (executive standard: GB T 19666-2005, GB

10. Cloth wires (voltage level: 300 500V 750V; Executive standard: GB5023-1997).

Legal basis: "Compilation of National Standards for Wires and Cables".

GB T 4011—1983 mm coaxial integrated communication cable.

GB T 4012-1983 mm coaxial integrated communication cable.

GB T General Principles of Test Methods for Communication Cables.

GB T 1985 Communication cable test method, working capacitance test, bridge method.

GBT T communication cable test method Capacitive coupling and capacitance unbalance test to ground.

GBT T communication cable test method Coaxial end-to-end impedance and internal impedance non-uniformity test pulse method.

Cable trays should be installed on buildings and structures (such as walls, columns, beams, floor slabs, etc.) as much as possible.

The general layout of the cable tray should be the shortest distance and meet the requirements of construction and installation, cable laying.

When the ladder frame or the perforated tray is laid horizontally, the height from the ground is not less than; The height of the trunking and non-perforated pallet from the ground is not less than. However, it is not allowed to be laid in a special electrical room (such as a power distribution room, an electrical shaft, and a technical floor).

When the bridge is laid vertically, the part below the ground should be protected by a metal cover, except when laying in the electrical special room.

When the cable tray is laid in multiple layers, the distance between the layers is generally as follows:

The upper part of the bridge should not be less than the roof or other obstacles;

The power cable tray should not be less than;

The control cable tray should not be less than;

Between the weak current cable tray and the power cable tray should not be less than, if there is a shielding cover plate can be reduced to.

The following cables of different voltages and different purposes can only be installed on the same layer of bridge and separated by partitions except because of the condition restrictions, should not be laid on the same layer of bridge:

cables above 1k and under 1k;

strong current, weak current, control cables;

emergency lighting and other lighting cables;

Dual power cables that supply power to primary loads.

When several groups of cables are laid at the same height, the needs of maintenance and overhaul should be considered between the adjacent cable trays, and generally should not be less than.

When the cable tray is laid horizontally, the support span is generally, and when the vertical is laid, the fixed point spacing is not more than 2m. When the bending radius of the bridge is less than 300mm, a support should be set up on the side of the straight section 300 600mm from the junction of the bending section and the straight section, and when the bending radius is greater than 300mm, a support and hanger should also be added in the middle of the bending section. 500mm internal support is provided at the three ends of the inlet and outlet boxes, cabinets, deformation joints and T-joints.

The cable tray can be fixed by pipe expansion bolts or welded on embedded iron.

When the cable tray passes through the wall and floor slab, fire isolation measures should be taken.

When the straight section of the steel cable tray exceeds 30m, and the aluminum alloy or glass fiber reinforced plastic cable tray exceeds 15m, there should be an expansion joint, and the connection should be a telescopic connecting plate. The cable tray spans the expansion joint of the building, and the expansion joint or expansion plate should be provided.

The cable tray should not be laid above the corrosive gas pipeline and the thermal pipeline and below the corrosive liquid pipeline, otherwise anti-corrosion and heat insulation measures should be taken.

Indoor cable trays, ladder frames should not be made of cables with jute or other flammable material outer sheath, otherwise in the indoor and cable trenches, tunnels, shafts with hemp sheath cables, should be stripped of hemp sheath, and the armor should be treated with anti-corrosion.

The specification for laying metal trunking shall be in accordance with the "JGJ16-2008 Code for Electrical Design of Civil Buildings".

Metal trunking wiring should be used in indoor places in normal environments, and metal trunking should not be used in places with serious corrosion. Enclosed metal trunking with a grooved cover that can be laid in the building ceiling.

All phase conductors and neutral conductors in the same distribution circuit should be laid in the same metal trunking.

The distribution line without electromagnetic compatibility requirements in the same path can be laid in the same metal trunking. The total cross-section (including the outer sheath) of the wires or cables in the trunking should not exceed 20% of the cross-section in the trunking, and the current-carrying conductors should not exceed 30. The total cross-section of wires or cables for control and signal lines should not exceed 50% of the cross-section in the trunking, and there is no limit to the number of wires or cables.

When the line with electromagnetic compatibility requirements is laid in the same metal trunking as other lines, the metal partition should be isolated or shielded wires and cables should be used.

Note: Control, signal and other lines can be regarded as non-current-carrying conductors. When laying more than three current-carrying wires or cables in the slot, when multiplied by the ampacities correction factor specified in Chapter 7 of the "JGJ16-2008 Code for Electrical Design of Civil Buildings", the number of wires or cables can be unlimited, and the total cross-section in the slot shall not exceed 20% of the cross-section in the trunking;

Wires or cables should not have joints in the metal trunking. When there are branches in the ** slot, the branch joints should be located in a position that is convenient for installation and inspection. The total cross-section of wires, cha hole cables and branch joints (including the outer sheath) should not exceed 75% of the cross-section in the trunking at the point.

Special accessories should be used for the line connection, corner, branch and terminal of the metal trunking wiring.

The metal trunking should not be laid above the corrosive gas pipeline and the heat pipeline and below the corrosive liquid pipeline, and anti-corrosion and heat insulation measures should be taken when there is difficulty.

When the wiring of the metal trunking is parallel or intersecting with various pipes, the minimum clear distance shall comply with the provisions of the table.

The parallel net distance between the metal trunking and the pipeline of the general process should be, and the cross net distance should be.

The net distance between the metal nucleus and the corrosive gas pipeline shall be parallel and the net distance of the cross shall be.

The metal trunking and the thermal pipeline have an insulation layer, and the parallel net distance should be, and the cross net distance should be.

There is no insulation layer between the metal trunking and the thermal pipeline, and the parallel net distance should be, and the cross net distance should be.

When laying metal trunking, it is advisable to set up hangers or brackets in the following parts:

1.The straight section is not more than 2m and the joint of the trunking;

2.the head of the trunking, the terminal and the junction box;

3.at the corner of the trunking.

Metal trunking must not be connected through floors or walls, etc.

The metal trunking and its bracket should be reliably grounded, and the total length should not be less than 2 places connected to the grounding trunk (PE).

When the length of the straight section of the metal trunking wiring exceeds 30m, it is advisable to set up an expansion joint; A compensation device should be set up at the deformation joint across the building.

Legal analysis: 1. Irradiated cross-linked power cable (voltage level: ; Executive standard: GB

2. Medium voltage XLPE insulated power cable (voltage level: 6 6kv-26 35kv; Execution standard: GB

3. High-voltage XLPE insulated power cable (voltage level: 64 110kV, executive standard: GB T 11017-[B]2002;127/220kv、290/500kv）

Fourth, the control cable (executive standard: GB9330-88; Module opening and voltage level: 450 750V).

5. Computer cable (voltage level: enterprise standard).

6. Overhead insulated cable (voltage level: ; Executive standard: three).

7. Aluminum stranded wire and steel-core aluminum stranded wire (voltage level: ; Executive standard: GB Hayano T 1179-1999).

8. Fire-resistant cable (voltage level: ; 6/1kv；Executive standard: GB T 19666-2005, GB

9. Low-smoke halogen-free cable (executive standard: GB T 19666-2005, GB

10. Cloth wires (voltage level: 300 500V 750V; Executive standard: GB5023-1997).

Legal basis: "Compilation of National Standards for Wires and Cables".

GB T 4011—1983 mm coaxial integrated communication cable.

GB T 4012-1983 mm coaxial integrated communication cable.

GB T General Principles of Test Methods for Communication Cables.

GB T 1985 Communication cable test method, working capacitance test, bridge method.

GBT T communication cable test method Capacitive coupling and capacitance unbalance test to ground.

GBT T communication cable test method Coaxial end-to-end impedance and internal impedance non-uniformity test pulse method.

Classification of burning characteristics of wires and cables and their standard tests.

According to their own combustion characteristics, wires and cables can be divided into ordinary wires and cables, flame-retardant wires and cables, fire-resistant wires and cables, halogen-free low-smoke wires and cables and mineral insulated cables.

1) Flame retardant wires and cables refer to wires and cables that are difficult to catch fire and have the ability to prevent or delay the spread of flames. The commonly used standard test is GB T18380 3 (equivalent to IEC60332-1999);

2) Fire-resistant wires and cables refer to wires and cables that can still maintain the integrity of the line under the flame combustion at the specified temperature and time. The commonly used standard test is GB T12666 6 (equivalent to IEC60331-21-1999);

3) Halogen-free low-smoke wires and cables are divided into flame retardant type and flame retardant and fire-resistant type. Flame retardant refers to wires and cables whose materials do not contain halogens, produce less smoke and dust when burned, and have the ability to prevent or delay the spread of flames. The commonly used standard tests are GB T17650 2 (equivalent to IEC60754-2), GB T17651 2 (equivalent to IEC 61034-2) and GB T18380 3 (equivalent to EC60332-3).

On the basis of the above, the flame retardant and fire-resistant type also needs to meet the requirements of maintaining the integrity of the line, and the commonly used standard test adds GB T12666 6 (equivalent to IEC60331);

4) Mineral insulated cable has non-combustible, smokeless and non-toxic properties in flames, and it will not cause disasters due to short circuits. In addition to the GB T12666 6 fire resistance test, the commonly used standard test should also be based on the actual fire situation, with reference to the British BS standard for the test of the cable with the standard requirements of anti-spray water and anti-mechanical impact (heavy object falling) ability. At the same time, you can refer to the national standard "Mineral Insulated Cables and Terminals with Rated Voltage of 750V and Below" (GBL3033-1991).