JPH01117204A - Laminate construction plate-type cable - Google Patents

Abstract

PURPOSE:To obtain a cable with a fireproof and insulating property stably by forming a bridging polyethylene, a fireproof sheath, and a resin sheath in order on phase-forming conductors which are made by furnishing parallel plural conductors with a fireproof layer wound with a fireproof insulating tape on the conductors. CONSTITUTION:Three plate-type cables CR, CS, and CT which compose phases of three-phase three-wire type cable respectively are provided on condition that they are laminated each other, the plate-type cables CR, CS, and CT are fastened integrally by fastening a cleat with the bolts and the nuts, and constructed keeping a specific laminate condition securely while maintaining a low impedance property. Each of the plate-type cables consists of a same structure, and a cable for one phase, CR for example, forms plural high insulating and fireproof layers 2 which are made by winding glass mica tapes on the halt-surface of the peripheries of plural conductors 1 made by winding plural soft copper wires concentrically to obtain a necessary conductor size responding to the capacity of the applied current. The fireproof layers 2 are formed side by side, and a bridging polyethylene layer 3 is formed to incorporate them together, on which a fireproof sheath 4 and a resin sheath 5 are furnished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is used as a low-voltage main line of about 600V in buildings, etc., and is stacked on top of each other to form a multi-phase multi-wire wA! Is
This type of laminated flat cable is used not only as a power line for ordinary electrical equipment, but also as a power line for emergency electrical equipment installed in case of a fire. Relating to the provision of laid flat cables.

[Conventional technology]

In recent years, as buildings have become taller, larger, and more sophisticated, measures to reduce voltage drops in low-voltage main lines within buildings have become increasingly important.

Conventionally, in view of this situation, flat cables in which multiple conductors are arranged in parallel and are collectively covered with a flat sheath have been provided as cables for low-voltage trunk lines that reduce voltage drop while reducing impedance. . A plurality of these flat cables shall be laid on top of each other using the flat surfaces of the flat sheaths and installed in a shaft, etc. in a building, so that the conductors of adjacent cables can be By taking advantage of the fact that the distance between cables is small and constant, each cable is responsible for each phase R, S, and T (N) of the multi-phase multi-wire line, thereby maintaining good low impedance characteristics. It is something.

By the way, in such a laminated flat cable, the plurality of conductors arranged in parallel within the flat sheath are either insulated all at once like the sheath, or individually insulated, and the insulation sheath and the flat sheath are insulated. The sheath is usually formed by extruding a heat-resistant insulating material such as polyvinyl chloride, so it cannot withstand use in emergencies such as fires, and since this type of flat cable is used as a main line, the cable It was requested that fire resistance be added to the

The inventors developed the structure of a fire-resistant electric wire that has already been developed and put into practical use, that is, a structure in which a mica tape wrapping layer as a fire-resistant layer and a plastic layer as an insulating layer in a normal state are sequentially provided on a conductor. We considered its use.

[Problem that the invention seeks to solve]

However, in the case of laminated flat cables, in order to maintain the overlapping state of the multiple flat cables that constitute each phase and to be overlapped with each other and to ensure the desired low impedance characteristics, the multiple flat cables that constitute each phase are overlapped with each other. The flat cables are clamped together with cleats or pressed against construction materials, and then integrated by tightening bolts.

In cables laid in this way, if the above-mentioned fire-resistant electric wire structure is adopted as is, the mica tape wrapping layer, which can maintain the highest insulation properties in the event of a fire, will be used as a fire-resistant layer to maintain the highest insulation properties in the event of a fire. It has a tendency to be easily destroyed by force, and it has been impossible to install it so that it will maintain its required electrical insulation layer in the event of a fire.

In addition, the resin sheath, which easily carbonizes in the event of a fire, clings to it and is difficult to peel off, and it adheres to the fire-resistant mica tape wrapping layer, making it difficult to maintain the required fire-resistant insulation performance in the event of a fire with the fire-resistant layer alone. It was impossible.

The present invention has been made in view of the above circumstances, and is a method for producing a laminated cable of this kind, which is capable of maintaining a stable fireproof insulation function in a flat cable in which a plurality of cables are stacked on top of each other and are fastened together in that state. The purpose is to provide flat cables.

[Means for solving problems]

The laminated flat cable of the present invention, which has been made to achieve the above object, consists of a phase-forming conductor constructed by arranging a plurality of conductors with a fireproof layer in parallel, which are constructed by wrapping a fireproof insulating tape around the conductor. A cross-linked polyethylene extrusion layer is provided, and a fire-resistant sheath made by extruding a flame-retardant insulator and a resin sheath made by extruding a resin are provided.

[Effect]

As mentioned above, the fireproof layer wrapped with mica tape or the like on the conductor has excellent physical strength and is located inside the sufficiently hard cross-linked polyethylene layer, so it is strong enough to use the fixing metal fittings required to fix the flat cables to be laminated. The cross-linked polyethylene layer absorbs the tightening force, and no excessive tightening force is applied to the mica tape-wrapped layer, so that it can be maintained as a prescribed fireproof layer until a fire occurs.

In addition, the fireproof sheath provided outside the crosslinked polyethylene layer and inside the resin sheath functions as a so-called carbide release layer that assists in peeling off even if the outer resin sheath becomes carbonized in the event of a fire. , it can also function as a refractory insulating barrier layer that prevents the carbide from touching the internal refractory layer.

〔Example〕

The accompanying drawing shows a preferred embodiment of the laminated flat cable according to the present invention, and as shown in the drawing, three flat cables C++, which constitute each phase of a three-phase three-wire line, Cs and Ct are provided in a state where they overlap each other, and by tightening the tightening bolt and nut of the cleat, the flat cables C++, Cs, and Ct are fastened and integrated, thereby maintaining a predetermined laminated state and reducing the It is provided for installation so as to possess impedance characteristics.

Now, the flat cable C+ that is provided for installation in this way
+, Cs, and Ct each have the same structure, and the flat cable equivalent to 1, for example C8, has a concentrically twisted structure using annealed copper wire as a wire so that the necessary conductor size can be obtained according to the current carrying capacity. A plurality of conductors 1 are prepared, a highly insulating fireproof layer 2 is formed by wrapping a single-sided glass mica tape around the circumference of each conductor, and the fireproof JIi 2 are arranged in parallel so that they are adjacent to each other. A conductor is formed, and a cross-linked polyethylene layer 3 that collectively covers the plurality of conductors 1 with a fire-resistant layer is provided on the outside of this group-forming insulated conductor, and a cross-linked polyethylene layer 3 is further provided on this layer by extruding a non-halogen flame-retardant polyolefin mixture. The structure includes a fireproof sheath 4 and a resin sheath 5 made of extruded heat-resistant resin such as PVC.

The cross-linked polyethylene layer 12 formed as described above not only functions as an insulating layer due to its electrical insulation properties, but also acts as an insulating layer due to the hardening properties and physical strength imparted by cross-linking. It also functions as a mechanical barrier layer that receives the resulting stress and prevents it from acting on the inside, thereby protecting the inner refractory layer 10.

Therefore, the layer thickness is also determined with consideration given to functioning not only as electrical insulation but also as a mechanical barrier.

A fire-resistant sheath made of extruded flame-retardant insulation can be easily peeled off even if the resin sheath is carbonized in the event of a fire, and the carbonized sheath material can cling to the fire-resistant layer wrapped with fire-resistant tape as internal fire protection. This makes it possible to ensure the specified fireproof insulation properties required in the event of a fire.

Note that the above embodiment shows the case where it is applied to a 3-phase 3-wire line, but for example, a 3-phase 4-wire line (R, S, T
, N), the number of cables increases or decreases depending on the configuration of the line, such as stacking four flat cables. In addition, the fireproof layer 2 and the fireproof sheath 4 may be used as long as they have properties equivalent to those listed above as suitable materials.
Such modifications may be made as appropriate within the scope of the technical idea of the present invention.

〔Effect of the invention〕

As is clear from the above explanation, according to the laminated flat cable of the present invention, a flat cable of this kind that can have a stable fireproof insulation function in a flat cable in which a plurality of cables are stacked on top of each other and connected in that state to be integrated. The intended purpose of providing a laminated laid flat cable has been achieved, and the practical effects are truly significant.

BRIEF DESCRIPTION OF THE DRAWINGS The attached drawing is an explanatory cross-sectional view showing one embodiment of the laminated laid flat cable according to the present invention. C++, Cs, Ct: flat cable, l
: Conductor, 2: Fireproof layer, 3: Crosslinked polyethylene layer, 4: Fireproof sheath, 5: Resin sheath.

Claims (3)

[Claims] (1) In a flat cable that constitutes each phase of a multi-phase multi-wire line and is connected and laid in an overlapping state, a plurality of conductors with a fire-resistant layer are formed by wrapping a fire-resistant insulating tape over the conductor. Laminated flat type, characterized in that a cross-linked polyethylene layer is provided on a phase-forming conductor made up of parallel conductors, and a fire-resistant sheath made by extruding a flame-retardant insulator and a sheath made by extruded resin are sequentially provided on top of the cross-linked polyethylene layer. cable. (2) The laminated laid flat cable according to claim 1, wherein mica tape is used as the fire-resistant tape as the fire-resistant layer. (3) The laminated laid flat cable according to claim 1, wherein a non-halogen flame-retardant polyolefin mixture is used as the flame-retardant insulator in the fire-resistant sheath.