摘要:
A polymer bushing includes a conductor bar, a conductor insertion hole at a lower end, a rigid insulator around the outer circumference of the conductor bar and having a receiving port for a cable termination, a polymer covering around the outer circumference of the insulator and a number of shades 4a formed separately along the longer dimension at the outer circumference. A large diameter part is provided above the conductor insertion hole which is in the vicinity of the lower end part of the insulator. A cylindrical shielding metal fitting is concentrically embedded together with the conductor bar in the large diameter part. An electric-field stress-control layer is provided at the interface between the large diameter part and the polymer covering.
摘要:
A polymer bushing includes a conductor bar, a conductor insertion hole at a lower end, a rigid insulator around the outer circumference of the conductor bar and having a receiving port for a cable termination, a polymer covering around 4 the outer circumference of the insulator and a number of shades 4a formed separately along the longer dimension at the outer circumference. A large diameter part is provided above the conductor insertion hole which is in the vicinity of the lower end part of the insulator. A cylindrical shielding metal fitting is concentrically embedded together with the conductor bar in the large diameter part. An electric-field stress-control layer is provided at the interface between the large diameter part and the polymer covering.
摘要:
A cable sealing end includes a base fitting configured for mounting on a base; a top fitting configured for securing an overhead conductor; an insulating body made of polymeric material; a conductive connection device configured to form a connection between a cable conductor and the top fitting; and a supporting element. The supporting element includes an elongated metal body; a top plate disposed on the elongated metal body and securable to the top fitting; and a metallic cylindrical structural component. The structural component projects into an interior of the insulating body and has a base flange disposed adjacent to the base fitting. The structural component has a length of one quarter to one third of a length of the insulating body. An entire length of the elongated metal body and the structural component, with the exception of the base flange, are embedded in the insulating body.
摘要:
An apparatus for sealing the end of an elongate cable such as a heating cable includes (1) a housing with a first open end and a second open end and a strain relief element positioned within the housing, (2) a flexible container which can be positioned over the cable end and (i) is of generally tubular shape, (ii) has an interior surface and an exterior surface, (iii) has a first open end and a second closed end, and (iv) contains a sealant; and (3) a cap which can be mated with the housing at the second open end, and cover the flexible container. The apparatus has excellent moisture-resistant properties even after repeated exposure to high temperatures, is reenterable, and can be readily mounted on a substrate such as a pipe.
摘要:
A novel high voltage power cable terminator of the type having a rigid insulating housing made of an inorganic material is provided which employs a pre-stretched elastomeric stress relief tube mounted on a removable core prior to installation to facilitate installation of the terminator upon a prepared end of a high voltage cable. The removable core is a generally cylindrical, helically grooved tubular structure. The stress relief tube is supported coaxially in a stretched condition upon the exterior of the core prior to installation. To install the stress relief tube on the cable, the prepared end portion of the cable is positioned within the hollow interior of the core, and the core is then removed to allow the elastomeric stress relief tube to contract and grip the peripheral surface of the portion of the cable where stress relief is desired.
摘要:
Terminations and splices in high voltage electrical cable can be shielded by shrinking over the termination or splice a heat recoverable hollow article which comprises a heat-shrinkable outer sleeve whose outer surface is anti-tracking at voltages of 2.5 KV and at least part of whose inner surface has a layer thereon which is solid at room temperature and which has electrical stress-grading character.
摘要:
A direct current cable, sealing end installation, the cable having a bared conductor end, a first semi-conductive screen around the conductor, a layer of insulating material around the screen, a second semi-conductive screen around the insulating layer and a conductive sheath around the second screen. The sheath the second screen and the insulating layer are stripped back to expose a portion of the second screen, a portion of the first screen and an intermediate length of the insulating layer. A hollow, cylindrical container with an inner diameter larger than the diameter of the cable extends lengthwise of the cable and from adjacent the bared conductor end to adjacent the sheath; and the container end adjacent the sheath has a liquid-tight connection to the sheath. The container is filled with liquid having a resistivity in the range from 10.sup.8 to 10.sup.6 ohm-meter to below the bared conductor end. Opposite ends of the liquid are respectively conductively connected to the bared conductor end and to the sheath. The length of the container and the liquid are sufficient to withstand the cable voltage between the conductor and the sheath. The conductor end and the insulating layer may be covered with tapes to prevent contact of the liquid therewith.
摘要:
A grounded surface distribution apparatus and system is provided including elastomer encapsulated cable terminals, joints, taps, load-break switches, current limiting fuses and surge protectors, each enclosed completely within a metal sheath combined in various arrangements to perform operational functions required in loop and radial underground distribution systems. The cable terminals include a soft dielectric filler making a void-free interfacial engagement with the surface of a hard dielectric filler of a mating component. To provide for breaking a coupling under load, an arc-quenching follower is retractable into an axial cavity in the coupling components of the system and projectable therethrough upon breaking of the circuit and disconnecting of the components to provide an improved arcquenching function. Thus, there is provided an underground system having security, operational safety and convenience.
摘要:
A cable termination is provided with a terminator having a rigid insulator suited for outdoor application and an inner stress relief element contained in the insulator. The terminator is applied in telescopic relation to a prepared end of a power cable which has a region of high electrical stress. The inner stress relief element includes a compressible portion having electrically conductive properties and forming a stress control shield, and a contiguous high dielectric strength portion. The two portions are related to one another such that the compressible portion provides continuous compliance of the stress relief element on the prepared cable end of any solid plastic or elastomeric insulated cable that is within a given range of cable sizes. The terminator may include a sealable compression lug for the making of an external electrical connection to the terminator.
摘要:
A stress grading coating for insulators comprising a non-linear semiconducting coating, such as silicon carbide, or the like using a glass binder having a fusion temperature of less than 850*C.