Medium-voltage fire-proof cable

Abstract

The invention relates to a middle-voltage power transmission fire-resistant cable, which is characterized in that a fire-resistant layer out of a middle-voltage cable core includes an inner fire-resistant inorganic fiber thermal insulating layer, and an outer composite fire-resistant thermal insulating layer, which is a soft thermosetting elastic body in normal use and is a fire-resistant thermalinsulating layer when exposed to fire, wherein the thermosetting elastic body consists of 30-50wt percent silicon-based elastic material, 40-60wt percent inorganic filling material, 5-15wt percent middle- and low-temperature frit, and 4-10wt percent vulcanizing agent and is prepared by mixing, extruding, shaping and vulcanizing. The composite fire-resistant thermal insulating layer is a soft protective material for ensuring the good bending property of the fire-resistant structure under normal condition, can change to tubular fire-resistant thermal insulating structure when exposed to fire orhigh temperature and can not be damaged for a certain time in fire environment so as to effectively prevent the flame or high temperature from damaging the inner insulating layer. When the outer flame temperature is 850DEG C, the surface temperature of the inner insulating layer is less than 180DEG C. The fire-resistant thermal insulating structure can be applied in common cable protection mannerand has very high production efficiency.

Description

technical field [0001] The invention relates to a medium-voltage fire-resistant cable, in particular to a medium-voltage fire-resistant cable with a soft fire-resistant structure in normal use and a hard-shell fire-resistant and heat-insulating structure in case of fire. Background technique [0002] For extra-large high-rise buildings, if 0.6 / 1kV low-voltage power distribution is used as usual, the amount of cables used and the workload of laying and installation will increase by tens of times compared with ordinary buildings, and the space for laying cables will increase by several times. Can, and too many and too large cables in the building will also have an adverse effect on safe use. Therefore, super-large high-rise buildings began to use medium voltage (6-35kV) power supply. As a fire-resistant cable, the low-voltage cable structure does not need to add an insulating shielding layer, so the fire-resistant insulating layer can be directly applied to the conductor, and...

AI Technical Summary

Problems solved by technology

The disadvantages of this cable: First, the fire-resistant structure is still a hard-structure fire-resistant cable, and second, the fire-resistant structure is still only suitable for low-voltage cables, and it is difficult to directly apply to medium-voltage cables

[0015] Therefore, so far, there has not been a medium-voltage fire-resistant cable that is fire-resistant under normal use conditions and has a soft structure, and can maintain normal power supply under dynamic conditions for a certain period of time after fire.

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