Abstract: A line break detection system for detecting a break in a conductor (1.004), the system including a first return signal generator (1.020) proximate a first end of a segment of the conductor, the first return signal generator being adapted to apply a first return signal to the conductor, the system including a first return signal detector (1.016) proximate a second end of the segment of the line, the second end being upstream of the first end, the first detector being adapted to receive the first return signal from the line, wherein the first return signal generator ceases to generate the first return signal if the line is broken.

Abstract: A cable adapted for suspension between poles in a single wire earth return application is composed of three elements; a core 2.030; a conductive layer 2.032 around the core, and a jacket 2.034 over the conductive layer. The core has high tensile strength to weight ratio and can be made of a composite material such as carbon fibre and epoxy. The conductive material can be aluminium. The jacket can be made from a material having electrical insulating properties. The conductive layer can be formed as a loose tube (7.072) around the core and drawn down to contact the outer surface of the core.

Abstract: The invention relates to a ceramifying composition for forming a fire resistant ceramic under fire conditions the composition comprising: (i) at least 10% by weight of mineral silicate; (ii) from 8% to 40% by weight of at least one inorganic phosphate that forms a liquid phase at a temperature of no more than 800° C.; and (iii) at least 15% by weight based on the total weight of the composition of a polymer base composition comprising at least 50% by weight of an organic polymer.

Abstract: A water detector wire 1.002 for use in a power cable or building, the cable having a wire 1.004 with a water soluble insulating jacket 1.006 made of two or more components, wherein a first component has a first solubility in water, and the second component has a second solubility in water, the second solubility being less than the first solubility. The second component can be substantially insoluble. On exposure to water, the soluble insulation 1.006 dissolves at the location of the water exposing the wire 1.004. This can be detected when the wire is close to a return path such as a return wire 4.038 or a cable screen 13.232. The location of a fault can then be detected by measuring the linear resistance of the wire. Two such wires 3.006, 3.007 can be used together.

Abstract: A fire resistant composition comprising: a silicone polymer; mica in an amount of from 5% to 30% by weight based on the total weight of the composition; and a limited amount of glass additive sufficient to enable the formation of a self supporting ceramic material at temperatures above the decomposition temperature of the silicone polymer and below the fire rating temperature of the composition. The glass additive addition required to produce the self supporting ceramic material has been found to be preferably from 0.3% to 8% by weight based on the total weight of the composition. The composition is applicable to products formed for fire wall linings, fire partitions, screens, ceilings or linings, structural fire protection, fire door inserts, window or door seals, intumescent seals, in electrical switchboard cabinets or cables. In one cable application, the composition may be used as the extruded intermediate material (2) between the conductor (3) and extruded sheath (4).

Abstract: A cable (1) comprises a conductor (3), an insulating layer (2) which forms a self-supporting ceramic layer when exposed to elevated temperatures experienced in a fire, and an additional heat transformable layer (4). The additional layer (4) can be another layer which forms a self-supporting ceramic layer when exposed to fire, or it can act as a sacrificial layer which decomposes at or below the temperature that the insulating layer forms a ceramic. The addition layer can enhance the strength of the layers before, during or after the fire, the structural integrity of the insulting layer (2) after the fire, the resistance of the layers to the ingress of water after the fire, or the electrical or thermal resistance of the layers during and after the fire.

Abstract: A cable (1) having a conductor (3), an insulating layer (2) which forms a self-supporting ceramic layer when exposed to elevated temperatures experienced in a fire, and an additional heat transformable layer (4). The additional layer (4) can be another layer which forms a self-supporting ceramic layer when exposed to fire, or it can act as a sacrificial layer which decomposes at or below the temperature that the insulating layer forms a ceramic. The addition layer can enhance the strength of the layers before, during or after the fire, the structural integrity of the insulating layer (2) after the fire, the resistance of the layers to the ingress of water after the fire, or the electrical or thermal resistance of the layers during and after the fire.

Abstract: A fire resistant composition comprising: a silicone polymer; mica in an amount of from 5% to 30% by weight based on the total weight of the composition; and a limited amount of glass additive sufficient to enable the formation of a self supporting ceramic material at temperatures above the decomposition temperature of the silicone polymer and below the fire rating temperature of the composition. The glass additive addition required to produce the self supporting ceramic material has been found to be preferably from 0.3% to 8% by weight based on the total weight of the composition. The composition is applicable to products formed for fire wall linings, fire partitions, screens, ceilings or linings, structural fire protection, fire door inserts, window or door seals, intumescent seals, in electrical switchboard cabinets or cables. In one cable application, the composition may be used as the extruded intermediate material (2) between the conductor (3) and extruded sheath (4).