| 摘要 |
<p>PURPOSE:To prevent spread of fire of line without big drop of allowable current, by covering the outside of a cable laid on a shelf with heat curing type sheet on which many small holes are drilled. CONSTITUTION:The outsides of cables 3, 3' which are laid on shelves 2, 2' in a hollow path 1 or a duct are intermittently covered with heat curing type thermal resistant sheets 4, 4' on which many small holes 5, 5', 5'' are drilled or with sheets that foamed thermal resistant paint is painted on one side face or both faces of those sheets. As above-mentioned thermal resistant sheets 4, 4', products that material which is flame retarder in usual time shows putty state and is cured and strengthened by heating is made to be sheet state of about 3-5mm thickness, or complexed sheets that aluminum foil or the like is papered on the product are used. It is preferable that small holes for ventilating 5, 5', 5'' have the diameters of about 3-7mm, intervals of pitches are about 25-50mm, and hole ratio is about 3-6%.</p> |
